Posts Tagged ‘noise exposure’

Can I Prevent My Hearing Loss From Getting Worse?

November 10th, 2011

By: Bettie Borton, Au.D., FAAA
Doctor of Audiology
Doctors Hearing Clinic
7025 Halcyon Park, Suite A
Montgomery, AL 36117
(334) 396-1635
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www.doctorshearingclinic.com

Bettie Borton, Au.D. Doctor of Audiology AudiologistWhen I diagnose patients with a loss of hearing, they usually want to know if there is any way they can stop the progression of the loss. Common sense (and a large body of research) tells us that hearing loss tends to get worse as we get older, but each case is unique. In many cases, hearing is stable for many years. In others, the hearing loss progresses relatively rapidly.

One of the most important things that all adults over the age of 50 need to do is to have an audiological evaluation that will establish their baseline hearing, and keep that on file with their primary care physician and with their health records kept at home. Getting a comprehensive audiometric  by a Board Certified Audiologist ensures that you have been evaluated by a professional who has the most training for this purpose, and ascribes to the highest ethical, practice,  and continuing education requirements available. Why is it so important to have this baseline? Well, if your hearing changes, it will be much easier to gauge the rate of progression of the loss if you have clearly established a “starting point”, and have annual re-evaluations to document any shift in thresholds. And remember, documenting that starting point could be very important –No one wants to borrow trouble, but  don’t forget that  17% of all of those involved in motor vehicle accidents with air bag deployment have permanent sensorineural hearing loss as a result! That could be difficult to prove in a court of law if you haven’t had a recent hearing test.

Noise is a leading cause of hearing loss, and hearing loss from noise exposure is usually preventable. Both the level of the noise and the length of time you’re exposed to it determine if a noise will cause damage to your hearing. A good rule of thumb is: if you have to raise your voice to be heard by someone standing three feet away, the noise around you could be damaging.  Everyday sounds, such as music, power tools, or a lawn mower, have been shown to cause hearing damage.

Visit a local hearing center for advice regarding the best options for ear plugs or other noise protection to wear during these activities and get your hearing checked on a a regular basis.  Your hearing professional can compare your exams over time to determine if your hearing loss is worsening. If a significant change is noted, your hearing professional may refer to you to an ear doctor for further evaluation.

 

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Posted in Audiological Evaluation, Audiometric, Baseline Hearing, Bettie Borton, Board Certified Audiologist, Doctors Hearing Clinic, Hearing Center, Hearing Damage, Hearing Loss, Hearing Professional, Hearing Test, Loss of Hearing, Noise Exposure, Sensorineural Hearing Loss, Uncategorized

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Sound Advice

October 6th, 2011

By: Dr. Amin Musani
Doctor of Audiology
The Hearing Clinic
119 W. Main Street
Denison, TX 75021
(903) 462-4022
www.thehearingclinic.org

I watched as the next IDPA shooter stepped up to the firing line. You could tell he had done this before. He carefully but purposefully loaded a magazine into his handgun and chambered a round. On cue, he drew and shot a perfect score in amazing time. His handgun seemed like an extension of his arm. The bullets landed exactly where he willed them to on the cardboard target. After safely holstering he stepped back, turned around and flashed a smile, which told you he was pleased with his results and all that training and endless hours of practice had finally paid off. As he made it back to the observer area I walked over and congratulated him for a job well done. Curious as to what type of handgun he was using I asked him, “What kind is it?” He replied, “It’s 2:30pm.”

It never ceases to amaze me the high number of shooters that I come in contact with that do not wear any type of hearing protection while shooting. Granted, some things in our lives we cannot control. However, noise induced hearing loss (NIHL) and Acoustic Trauma are phenomenon that we most certainly do have control over and yet many shooters ignore the very basic principle of wearing hearing protection.

When is firearm noise is too much? When do we cross that line between loud and damagingly loud? Table 1 [1] displays some of the decibel (dB) levels of various sounds found in our daily lives. A decibel is a unit of measurement and for our purposes here it is measured on a logarithmic scale and there is a 10-fold increase in noise energy for each 10 dB increase. Said another way, an increase of 10 dB doubles the loudness level.

Sounds over 140dB can cause pain, and prolonged exposure to noise over 85-90dB can result in permanent hearing loss. Gunfire may be categorized as an impulse noise, which has the characteristic of an explosive burst. Impulse noise of sufficient intensity and pressure is often a cause of acoustic trauma. Generally, studies have shown that such impulse sounds may result in the shifting, skewing, bending, swelling, bursting, tearing, fusing &/or severe mechanical damage to the inner ear cells, structures, and auditory pathways. That is, short-duration sounds of sufficient intensity (e.g., a gunshot or explosion) may result in an immediate, severe, and permanent hearing loss, which is termed acoustic trauma. The degree of hearing impairment seen after acoustic trauma varies and may range from a mild to profound hearing loss.

Figure 1 (Pickles & Heumen; 2001) compares electron microscopy of normal, healthy outer hair cells (specialized hearing cells in our inner ear) to damaged ones. Once such damage occurs, it is permanent. There is no method of regenerating these cells or “curing the damage.” Bear in mind that this is only one site where such damage can occur from noise exposure along our auditory pathway.

There is evidence to suggest that once deterioration of certain specialized hearing cells (spiral ganglion cells) has begun, there is a corresponding deterioration within the central nervous system at areas higher up in the auditory system (Kim et al., 1997; Morest et al., 1998). Thus, once damage has occurred at lower levels it is not isolated there but rather may progress upwards through the auditory pathway. This is very characteristic of impulse noise such as gunfire that causes acoustic trauma. The inner ear, then, is not the only structure at risk from such exposure.

Figure 1. Normal, healthy outer hair cells (L) vs. damaged outer hair cells (R).

Virtually all of the structures of the ear and hearing system can be damaged from gunfire noise (NIH Consensus Statement; 1990). Generally, for sound levels below 140 dB, different types of sounds produce the same hearing loss. This does not appear to be the case at levels above 140 dB, where impulse noise creates more damage than would be predicted. This may imply that impulse noise above a certain critical level results in acoustic trauma from which the ear cannot recover (NIH Consensus Statement; 1990).

Exposure to noise between 90 and 140 dBA (dBA denotes a decibel measure made with a filter that adjusts for human auditory sensitivity) damages the inner ear metabolically rather than mechanically and causes injury depending on the level and duration of exposure. Noise-induced hearing loss, in contrast to acoustic trauma, develops slowly over years, and is caused by any regular and consistent exposure exceeding a daily average of 85-90 dBA (Clark & Bohne; 1999). Acoustic trauma may occur from just one unprotected exposure to gunfire noise.

For sounds between 75 – 90 dBA, the ear has a natural protective mechanism to reduce its sensitivity to low frequency impact sounds through what is termed the middle ear reflex. Generally speaking, muscles in our middle ear contract and stiffen three tiny bones (the smallest bones in the human body called ossicles; see Figure 2) that relay sound to the inner ear. However, a delay of 300 to 500 milliseconds is required to set this protection fully in operation. Most naturally occurring impact sounds can easily be dealt with by the middle ear, but many man-made sounds, such as explosions from guns, as well as certain industrial noises, occur so quickly that our middle ear protective mechanism cannot respond quickly enough. The hearing loss caused by such sounds is permanent acoustic trauma (Truax; 1999).

Peak sound levels from rifles and shotguns can range from 132 dB SPL (sound pressure level is another unit of measurement) for small-caliber rifles to more than 172 dB SPL for high-powered firearms. Americans collectively own more than 230 million guns, and more than half of men in the American industrial workforce occasionally use guns. The National Rifle Association estimates that 60 to 65 million Americans collectively own more than 230 million guns. Because guns are so prevalent in our culture, shooting firearms is the most important source of excessive noise outside the workplace. The severity of injury produced by impulsive noise exposure and the prevalence of shooting by Americans makes gun noise America’s most serious non-occupational noise hazard. The acoustic energy in a single report from a high-powered rifle or shotgun is equivalent to almost 40 hours of continuous exposure at 90 dBA. In other words, 1 bullet equals 1 week of hazardous occupational noise exposure. An avid target shooter can be exposed to an entire year’s worth of hazardous occupational noise in just a few minutes (Clark & Bohne, 1999; NRA, 1999).

What about firearms themselves? Is a .22LR any better on your ears than a .45ACP? Table 2 [2] compares the dB levels of various cartridges.

Recall that sounds over 85-90 dB can lead to permanent hearing damage without hearing protection. As can be seen from Table 2, even firing a .22LR (134 dB) has the potential of causing permanent, irreversible, inner ear damage.

There are various kind of hearing loss. Conductive hearing loss refers to physical damage, infection or fluid build up in the middle ear cavity (Figure 2). If the gunblast is of sufficient intensity a conductive loss may be seen and accompanied by such symptoms as eardrum rupture or middle ear bone damage.

Conductive losses are typically open to medical treatment from a physician who specializes in diseases of the ear (Otologist or Otolaryngologist). Sensorineural hearing loss refers to damage within the inner ear. This is usually, incorrectly, referred to as “nerve type deafness” which really only occurs in about 1% of the American population (Mueller and Hall, 1998). Sensorineural hearing loss is the most common type of hearing loss in America, and noise induced hearing loss or acoustic trauma from firearms is typically sensorineural. It is permanent, irreversible and with proper hearing protection, can be avoided or minimized.

Probably the most common excuse I have heard from shooters is that “my ears have toughened up from shooting and I don’t have to wear hearing protection.” Well, I’m sorry to say that this is not possible. What is more likely is that you have sustained sensorineural hearing loss and some sounds just don’t seem as loud any longer (along with speech). However, it is still critical to wear hearing protection as the hearing you do have left can still be harmed from unprotected firearm exposure. As researchers and educators have noted, “Ears don’t get tough, they get deaf.” (Mueller & Hall, 1998).

Typically, noise induced hearing loss and acoustic trauma affect the high frequencies first. Our ears respond to sounds across a wide range of frequencies, from about 20 to 20 000 Hertz (Hz). Speech frequencies are roughly located between 250-8000 Hz. Low frequencies are used to “hear people” while the highs are what we use to understand what they say. To put it another way, the power of speech (vowels) is located in the low frequency range while the clarity of speech (consonants such as s, k, th, sh, f, th) is located in the highs. High frequency consonants are necessary to maximize speech intelligibility. Noise damage from firearms affects these high frequencies first due to, some believe, anatomical reasons (Mueller & Hall, 1999). Figure 3 [4] depicts an audiogram (record of one’s hearing) of a sensorineural hearing loss typical of shooters.

As such, many people complain that “I hear people, but sometimes I don’t understand what they said.” Women’s and children’s voices, typically in the high frequency range, are usually the most difficult to understand when one has such a high frequency hearing loss. Add to all this that our hearing gets worse just from the normal aging process and you quickly realize just how important hearing protection really is.

Other factors also determine how susceptible one is to firearm noise exposure. For examples, blue-eyed individuals may be more susceptible than people with greater melanin content in their eyes. Some studies have shown that males are more susceptible to noise induced hearing loss (NIHL) than females. Newborns and older individuals also seem to be more likely to develop hearing loss from NIHL. Finally, some studies have also shown that smoking increases one’s chances of acquiring hearing loss from noise. This may be due to the carbon monoxide in the smoke (Henderson, Subromaniam, & Boettcher; 1993).

I’ve also noticed that some shooters will wear their hearing protection, but only while shooting. When observing from just a few yards away, they do not wear their hearing protection. This is simply not good hearing conservation practice and is against competition rule #7 of your IDPA manual. In fact, if one was to comply with this rule, anyone within 50 yards of the firing line must wear not only hearing protection, but eye protection also. Some handguns at IDPA produce a very discernible boom that can still damage your ears (see Table 2), even if you are not shooting and are only a few feet to yards away. Of course, this will vary with the type of firearm, cartridge, and distance from the shooter, but Table 2 clearly shows that even a report from a .22 can damage your ears. Though not relevant to IDPA purposes, the use of muzzle brakes and ports dramatically increases the level of noise exposure from firearms.

In the consideration of sounds that can damage hearing, one point is clear: it is the acoustic energy of the sound reaching the ear, not its source, which is important. That is, it does not matter if the hazardous sound is generated by a machine in the workplace, by a loudspeaker at a rock concert, by a lawnmower or a firearm during an IDPA event. Significant amounts of acoustic energy reaching the ear may create damage–at work, at school, at home, or during leisure activities. Although there has been a tendency to concentrate on the more significant occupational and transportation noise, the same rules apply to all potential noise hazards, including and especially firearms (Clark and Bohne; 1999).

Sound advice dictates that when at the gun range, by all possible means, take appropriate measures to practice safe gun handling. Wearing hearing protection (along with eye protection) falls into this category, whether you are the shooter or an observer. Think of it this way: hearing aids could cost you anywhere from $600 to $8000 per pair! Protect your hearing and you could spend that on more important things…like firearms, ammunition, training & IDPA.

References
  • American Academy of Audiology. http://www.audiology.org/consumer/guides/aural.php
  • Clark, W.W. & B.A. Bohne (1999). Effects of noise on hearing. Medical Student Journal of American Medical Association. May 5th, Vol. 281: 17.
  • E.A.R., Inc. (2001). http://www.earinc.com/howhearingworks.html
  • Henderson, D., Subromaniam, M., & Boettcher, F. (1993). Individual susceptibility to noise-induced hearing loss. Ear and Hearing, 14(3): 152-156.
  • Kim, J., Morest, D.K., and Bohne, B.A. (1997). Degeneration of axons in the brain stem of the chinchilla after auditory overstimulation Hear Res, 103:169-191.
  • Kramer, W. Gunfire and Hearing Protection. Ball State University, Muncie, Indiana.
  • Mestel, R. (2000). Los Angeles Times. Original print date February 28, 2000. http://www.audiology.org/consumer/guides/aural.php
  • Morest, D.K., Kim, J., Potashner, S.J., and Bohne, B.A. (1998). Long-term degeneration in the cochlear nerve and cochlear nucleus of the adult chinchilla following acoustic overstimulation. Micro Res Tech 41:205-216.
  • Mueller, H.G. & Hall, J.W. (1998). Audiologists’ Desk Reference. Vol. I Singular Publishing: San Diego
  • Mueller, H.G. & Hall, J.W. (1998). Audiologists’ Desk Reference. Vol. II. Singular Publishing: San Diego.
  • National Rifle Association (1999). Fact Card. http://www.nraila.org/research/99fctcrd.htm.
  • NIH: National Institute of Health Consensus Statement Noise and Hearing Loss. Online 1990 Jan 22-24;8(1): 1-24. http://text.nlm.nih.gov/nih/cdc/www/76txt.html
  • Pickles, J., & Heumen, W. (2001). Hearing Unit. Vision Touch and Hearing Research Centre, University of Queensland. http://www.vthrc.uq.edu.au/hearing/hearing_home.html
  • Truax, B. (1999). Handbook of Acoustic Ecology (2nd Edition). Cambridge Street Publishing.

Dr. Amin Musani is a Clinical Audiologist practicing in Denison, TX. Any comments or questions may be directed to DrAminMusani@cableone.net or The Hearing Clinic 119 W. Main St. Denison, Texas, USA 75021, Phone: (903) 463-9900, FAX: (903) 463-9911.

[1] Mueller and Hall (1998).

[2] William Kramer, Ph.D.

[3] Mestel, 2000.

[4] E.A.R. Inc.

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Posted in Audiologist, Clinical Audiologist, Decibles, Decreased Hearing, Ear Protection, Hearing Aid, Hearing Care, Hearing Damage, Hearing Loss, Noise Exposure, Noise Hazards, Noise levels, Noise-induced, Protecting Ears, Texas

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Otoprotectants for Noise Induced Hearing Loss

June 29th, 2011

Hearing Professional Center
By: Allison McKenzie , Au.D.
Doctor of Audiology
5462 Glen Lakes Drive
Dallas, TX 75231
(214) 987-4114
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www.hearing-center.com

Noise induced hearing loss (NIHL) is the second most common cause of sensorineural hearing loss (SNHL) in industrialized societies. Excessive noise exposure is the only preventable cause of SNHL (Kopke, 2007). The hair cells of the inner ear are the specific structures damaged by excessive noise exposure and, in mammals, are unable to regenerate spontaneously. This physical damage can cause permanent and irreversible hearing loss as well as degrade a person’s quality of life. Knowing how the physical structure is affected by noise can aid researchers in their search for therapeutic agents that act as otoprotectants against NIHL (Ciorba et al, 2008). Personal hearing protection devices along with environmental engineering are the most prevalent protection methods of hearing conservation programs. Even with the required participation in hearing conservation programs, by workers who are exposed to noise at or above the action level, NIHL is still quite common. The current methods of protection are limited in their ability to save every listener from a NIHL. Researchers are actively searching for a pharmacologic approach that, when combined with environmental engineering and personal hearing protection devices, will more completely protect people from NIHL (Kopke, 2007).

Antioxidants

Vitamin E

Oxidative stress has been proven to contribute to the degradation of hair cells in the cochlea. Drugs with antioxidant properties, such a vitamin E, have been tested on both animals and humans. The success with vitamin E as an otoprotectant in animals is far greater than the results seen is human subjects. The different effects of antioxidants between human and animal subjects may be due to differences in pharmacokinetic and pharmacodynamic principles. More research is needed to determine when and in what intervals antioxidant treatments are needed to be the most useful in preventing NIHL in humans (Fetoni et al, 2008).

N-acetyl-l-cysteine (NAC)

The glutathione pathway is a very important antioxidant pathway in the cochlea. NAC acts as a glutathione substrate and aids the body in glutathione synthesis. Research shows the effectiveness NAC has on NIHL when given intraperitoneally and via oral gavage. ABR recordings on chinchillas show the differences between dosing methods and different types of noise exposure. Many studies have shown the otoprotectant effectiveness of NAC in animal subjects, but this particular study chose to administer high-kurtosis noise in order to simulate a typical industrial environment. The goal was to show whether NAC would be considered an effective treatment method in human subjects with a NIHL (Bielefeld et al, 2007).

Clifford and Rogers (2009) looked at the effect of antioxidants as otoprotectants for impact noise trauma. They stated that people who are exposed to impact noise are at greater risk for NIHL. They chose to study the otoprotectant effect of NAC on chinchillas. The antioxidant effected the way the cochlea reacted to changes in oxygen and nitrogen which helped protect the inner ear from severe hair cell damage. There were limitations to this study due to the difficulty the researchers faced when trying to measure the physical changes during impulse noise stimulation. Clifford and Rogers (2009) cite the work of Kopke’s unpublished pilot study of 566 Marine recruits which reported a 25% reduction in the number of Marines suffering a NIHL after a two-week period of M16 rifle exposure. These Marines were given NAC as the antioxidant otoprotective agent. There is more research on the usefulness of antioxidants as otoprotectants currently being conducted with military personnel.

A study conducted in 2006 looked at NAC given thirty minutes prior to exposure to loud music. This is the only study that administered the NAC by effervescent tablet form. The results indicated that the results from the NAC group were no different than the results from the placebo group. The author pointed out other research that suggests dosing schedule is very important to the success of NAC in preventing permanent threshold shifts (Kramer et al, 2006).

Hearing Professional Center StaffHPC Staff: (From Left) Dr. Allison McKenzie, Jared Lacy & Dr. Deborah Price

C-Jun N-terminal Kinase (JNK) Inhibitors

JNKs are stress activated protein kinases that have been shown to be responsible in the apoptosis or death of oxidative stress-damaged cells. Knowing the signaling chain of JNKs can effectively help researchers provide otoprotectants that are efficient in preventing cochlear damage. JNK inhibitors are cell permeable peptides that target specific protein groups and block the JNK from carrying out its natural course in the cell. One research study showed that the  peptide conjugate D-JNKI-1 can be injected locally to the scala tympani of explanted cochleas to provide protection from acoustic trauma as well as aminoglycosides. JNK inhibitors as otoprotectants have shown the ability to keep a temporary threshold shift from becoming a permanent hearing loss (Zine and Van de Water, 2004).

A more recent study looked at the effect of JNK inhibitors on patients whose hearing was affected by firecrackers on New Year’s Eve. The 11 subjects were selected within 24 hours of the firecracker display and had at least a 30 dBHL loss at 4 and 6 KHz. The subjects were given topical anesthesia and then given a single intratympanic injection of either .4 or 2.0 g/ml of the JNK inhibitor AM-111. The results showed no difference between the dosage groups. The study shows improvement in the thresholds of all 11 subjects, but there was not a control group to compare these results to. There is not enough evidence to say that AM-111 should be used clinically to treat acute acoustic trauma (Suckfuell et al, 2007).

Coenzyme Q10

Coenzyme Q10, which is used to increase cellular metabolism, was used to determine otoprotective effectiveness in 30 guinea pigs. The coenzyme Q10 was given intraperitoneally 2 hours before the guinea pigs were exposed to 130 dBSPL of noise centered at 4 KHz for 3 hours. ABR was used to measure pre and post results. The guinea pigs showed no differences in ABR recordings prior to noise exposure, but 7 days after the exposure the treatment group showed less of a shift than the control group. There was a marked improvement in antioxidative activity noticed 2 days post coenzyme Q10 injection (Hirose et al, 2008).

Hepatocyte Growth Factor (HGF)

HGF is a protein responsible for cell growth and different morphogenic factors. Gelatin hydrogels that had been dipped in either HGF or saline were placed on the round window of 18 guinea pigs 1 hour after a 3 hour exposure to 120 dBSPL noise. The results were measured using ABR throughout the testing process. The ABR results showed that the guinea pigs who were given the gelatin hydrogels dipped in HGF had better ABR thresholds than the saline group. The results differed in the basal portion of the cochlea only. The apical region remained unchanged for both groups (Inaoka et al, 2009).

Tacrolimus (TCR) and Melatonin (MLT) vs. Dexamethasone (DXM)

A recent study compared TCR, MLT and DXM under the same conditions to determine which if any was the most effective otoprotectant. TCR is a calcineuron inhibitor that was administered to a group of rats the day before exposure to traumatic noise and for 14 days following the noise exposure. The TCR group of rats showed an improvement in ABR thresholds within one week post noise exposure. The rats given MLT, a pineal gland hormone and antioxidant, were reported to show a marked improvement in ABR thresholds by week three post noise exposure. The group given DXM, an anti-inflammatory and immunosuppressant, showed no difference in ABR threshold recordings from the control group (Bas et al, 2009).

Implications

Most of the research on otoprotectants that has been published is based on an animal model. There are a few human subject based articles, but the methods of otoprotectant use are varied. The study that looked at the effect of NAC on people exposed to loud music used an effervescent tablet. I question whether the outcome would have been different if the dosing method had been different. My concern is the feasibility of intratympanic injections every time a person is exposed to excessive amounts of noise. More research is needed to determine which of the treatments presented in this paper are useful clinically. Every research article mentioned the need for more research to fully understand how the system works. I would like to see more human subject research to better understand how an otoprotectant might be most effective.

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Posted in Cochlea, Dallas, Hair Cell Damage, Hearing Conservation Programs, Hearing Loss, Hearing Professional Center, Hearing protection, inner ear, Noise Exposure, Noise Hazards, Noise levels, Noise-induced, Otoprotectants, Sensorineural Hearing Loss, Texas, Uncategorized

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Protect Your Hearing. It’s Never Too Late.

December 10th, 2010

Hearing Professional Center
By: Deborah Price, Au.D. & Allison McKenzie     
5462 Glen Lakes Drive
Dallas, TX 75231
(214) 987-4114
www.hearing-center.com

The hearing system and the ability to use it are more complicated than most people might think. Hearing is often taken for granted until people find themselves having difficulties communicating. People often say they hear, but cannot understand what others say. There are many reasons why the ability to hear can become abnormal, but one of the most common causes of damage to the ear is through noise exposure. Gunfire is a large contributor to hearing loss. Luckily, unlike other causes of hearing loss, damage from noise exposure due to gunfire can be prevented through the use of ear protection. A variety of products are on the market that can be used for this purpose, ranging from the standard foam over-the-counter earplugs to custom-made amplified ear protection.

The auditory system itself is complicated and delicate, and can be divided into three sections: the outer, middle, and inner ear. Sound travels in waves through the environment to the outer ear. The outer ear directs the sound down the canal to the eardrum. The eardrum is the dividing line between the outer and middle ear. When sound enters the ear canal, the eardrum and the bones behind it vibrate, transmitting the sound through the middle ear to the inner ear. The inner ear contains the fluid-filled cochlea, which is shaped like a snail shell and contains many delicate cells. Cells in the cochlea are called hair cells and are tuned to specific frequencies. The hair cells respond to frequencies from 50 to 15,000 Hz (cycles per second). Hair cells turn sound into nerve impulses, which are sent to the brain to be processed via the auditory nerve.

There are many reasons why the ability to hear can become limited. Genetics, heredity, disease processes, medications that are toxic to the ear, the aging process, and trauma can all cause hearing loss. Damage to the auditory system can be medically treatable or permanent, depending on where and how the damage occurred. Outer and middle ear damage is called a conductive hearing loss and is often treatable through medical intervention. Damage to the inner ear is a sensorineural hearing loss and is often treatable through medical intervention. Damage to the inner ear is a sensorineural hearing loss (or nerve loss). Noise exposure is the most common cause of permanent hearing loss today and can occur from various sources, such as machinery, engines, music, and explosives.

Noise damage depends on several factors: how loud the sound is, the length of exposure to the sound, and whether or not the person is predisposed to hearing loss by heredity. Fortunately, two of the three factors can be controlled. Loudness plays a huge role with noise damage. Loudness levels of different sounds are measured in decibels. Fifty to 60 decibels is the approximate loudness level of normal conversational speech, 80 decibels approximates the loudness level of a busy intersection, and 130-155 decibels or greater approximates the loudness level of jet engines and gunfire. Exposure to sounds equal to or in excess of 85 to 90 decibels for an extended period of time is damaging to the auditory system. Thus, exposure to gunfire is well outside the safe range for hearing.

Duration is also a big factor regarding exposure to gunfire. Hearing loss can result from one-time, repeated, and/or long-term exposure to loud sounds. The more frequently a person is exposed to gunfire, the more his or her ability to hear can be damaged.

Why is this important? Due to the shape of the cochlea and the frequency components of noise, the ability to hear in the higher frequencies will decrease first if hearing protection is not used when firing a gun. Most speech cues fall between 500 to 4,000 Hz, with vowels being low pitched and consonants being high pitched sounds. Hearing loss due to noise typically occurs around 4,000 Hz. With increased exposure, hearing sensitivity in this region will decrease and hearing loss will start to encompass neighboring frequencies. The resulting damage is permanent and effects communication abilities by limiting the audibility of consonant sounds. Often, amplification in the form of hearing aids will compensate for the hearing loss. There is also a high correlation of tinnitus, or ringing, in the ears of people with noise-induced hearing loss. Tinnitus has been reported to be very frustrating and annoying by some sufferers.

Fortunately, the effects of damage from gunfire can be prevented or greatly reduced with the use of hearing protection. Appropriate hearing protection depends on the circumstances surrounding the use of firearms, as well as the needs of the wearer. No single form of hearing protection is appropriate for every situation. A licensed audiologist is the best source for guidance in choosing appropriate hearing protection.

All hearing protection falls under two categories: earmuffs and earplugs. Both types of protection reduce the amount of loudness traveling through the ear and have varying range of sophistication. Earmuffs fit snuggly over the ears and are attached to a headband. Earmuffs vary in the level of complexity. Unsophisticated models are relatively inexpensive and reduce the loudness level of sound reaching the ear by insulating the ear. Sophisticated electronic models can incorporate either compression circuits that allow the loud sounds to reach the ear at a reduced loudness level, or amplifiers that increase the loudness for soft sounds only. It is important to note sufficient tension must be obtained from the headband to insure a seal is made around the ears. Many sportsmen and sportswomen find earmuffs cumbersome and uncomfortable.

The other category of hearing protection is earplugs. Earplugs also reduce the amount of loudness traveling through the ear and have a varying range of sophistication. Earplugs come in different types of materials and serve different purposes. Some are available over-the-counter, and others are custom-made. Regardless of the material used or the level of sophistication, all earplugs fit in the same part of the ear, the outer ear canal.

The two main types of over-the-counter earplugs are foam plugs and Sonic Valves. The major benefit of foam plugs is they are inexpensive and can be found in most drug and grocery stores. Foam plugs, when inserted properly, are effective sources for protection against noise damage. Ear canals vary greatly in size; some are small with bends in them, and few are straight like a pencil. Because of varying canal sizes and shapes, foam plugs are often inserted incorrectly, which reduces effectiveness. Foam plugs cannot be adequately cleaned and may be uncomfortable for extended use. Foam earplugs need to be replaced routinely.

Another cover-the-counter earplug, Sonic Valves, is relatively inexpensive and can be found in sporting goods stores. Sonic Valves are popular because they enable the user to hear conversation better than with a standard solid foam plug. The Sonic Valve has an acoustic filter that is activated when loud sounds occur, blocking these sounds from entering the ear. The Sonic Valve is shaped much like a Christmas tree, enabling it to fit a variety of ear canal sizes. Again, proper insertion is key to the effectiveness of the plug. Discomfort is also a major complaint.

Custom earplugs have gained popularity with people who use firearms. Custom plugs are desirable because they provide a more comfortable fit and are easily cleaned. Custom plugs are more expensive than foam plugs and require an ear mold impression of the ear canal. To obtain optimum noise reduction, the custom plugs must fit snuggly in the ear. There are two general types of custom plugs: solid and filtered.

The solid plug is excellent for blocking damaging noise levels. Solid plugs work well for target shooting. For maximum protection, solid plugs can be used in conjunction with earmuffs, which is best for white wing dove hunting. A common complaint regarding solid custom earplugs is the diminished ability to hear speech. Filtered custom earplugs help solve some of this problem. Custom filtered earplugs are similar to Sonic Valves in function but are very comfortable to wear. Filtered plugs allow for conversation (at a reduced volume) and protect the user when loud sounds occur. Some of our patients have reported when mowing the lawn, the mower is quiet yet they can hear approaching cars. Filtered plugs are excellent for the shooting range and all kinds of hunting environments. Filtered plugs are easy to insert, are comfortable, and provide an overall reduction of hazardous noise. For the past 28 years, we have recommended the filtered custom earplug as general, all purpose protection for all our patients who hunt.

Amplified earplugs are the latest and most sophisticated form of hearing protection on the market. Amplified earplugs enable the user to hear everything much louder than normal except gunfire. These plugs shut down to protect the user’s hearing when a rifle, shotgun, or handgun is discharged. Amplified earplugs are available in automatic or manual versions. Both models can be made out of soft or hard material. The benefit to the avid hunter is the increase in loudness of soft sounds, such as leaves rustling, traps releasing, animals moving, and danger approaching. Amplified earplugs also allow for conversation to be easily heard. The automatic model shuts off the amplification and blocks the sound when firearms are discharged, limiting the loudness of the noise going into the ear. The manual model has a booster switch that must be manipulated manually to increase loudness for soft sounds and must be turned off prior to firearm discharge to protect against the damaging effects of gunfire.

Amplified earplugs are a custom product and need to be molded to the shape of the ear and ear canal. Proper fit is critical for protecting the ear from the gun blast. Due to the electronics available in amplified earplugs, they can be a little pricey. The plugs are battery operated, and both models contain a manual volume control.

Firearms are used in a variety of different settings and circumstances. Regardless of the situation, it is imperative to use hearing protection any time a firearm is discharged. Not only does ear protection preserve hearing, certain models can enhance the hunting experience. Men and women everywhere enjoy the sport of hunting wild game as well as the challenge of shooting targets. Protecting against noise-induced hearing loss does not have to reduce enjoyment received from excelling in shooting sports. Remember, any time firearms are discharged without ear protection, whether at a target range or out in the wilderness, damage is occurring to the shooter’s ability to hear. Protect your hearing. It is never too late.

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Hunters: Protect Your Hearing!

November 19th, 2010

Hearing Professional Center
Deborah Price, Au.D.
Doctor of Audiology      
5462 Glen Lakes Drive
Dallas, TX 75231
(214) 987-4114
www.hearing-center.com


Dr. Price is often asked by people she meets, “How did you get involved with Hunting?”

Early one morning in May 1983, Bill Weiss walked into her office to see if he could have his hearing tested.  At the time, Dr. Price was sitting on the floor, barefoot, with a paint brush in her hand.  She had opened her office several months earlier and was still putting the finishing touches on the construction.  Bill reported an extensive history of noise exposure from his favorite past time….hunting.

All her life she had wanted to hunt but her Father didn’t hunt, her brother didn’t hunt, and when she married, her husband didn’t hunt.  Of course girls didn’t hunt anyway did they?

As Dr. Price started working with Bill and his hearing loss he would share his stories and pictures about his hunting expeditions.  She had never known anyone who had been to Africa on Safari.  Her only exposure had been in movies and documentaries.  Bill had not only been to the Dark Continent but Spain, Argentina, Alaska, and other exotic destinations in the pursuit of animals. 

Bill shared stories of tiger, elephant, spiral horned antelope and rhino hunts.  He was always talking about the Dallas Safari Club.  Bill talked to Carla Peterman and Ginny Etheridge (convention organizers) about letting her exhibit at the 1986 Annual Event.  Dr. Price was accepted, given a booth, conducted hearing screenings and sold ear protection.  

Every year thereafter, Hearing Professional Center had a booth at the convention.  Dr. Price has displayed all kinds of products and devices for hearing impaired people.  She has tried to encourage hunters to wear shooting protection.  In 22 years she sees how far we have come in protecting ears from noise exposure. 

In June 1991 Dr. Price was asked to join the DSC as a member.  There were very few female members at that time and she was honored to have been asked.  She realized you cannot hang around hunting people without taking up the sport yourself.  She was actively involved in the Ladies Luncheon when it first began.  During one of the early years she went in with 3 other ladies to buy a Safari in South Africa with Conrod Vermoch.  She thought she better learn how to shoot if she was going on Safari herself.  

For the next year Dr. Price practiced shooting a Browning 22 with a Leupold 3.5×10 scope.  After going through 2 bricks of shells and grouping her shots in a 1 inch pattern, she picked up a larger gun.  She was handed a 300 Weatherby which knocked her off her feet.  She soon realized what kick meant!

Once Dr. Price knew she could shoot, she needed to know if she could “kill” an animal.  At a DSC monthly meeting, she bought a Blackbuck Antelope Hunt at the 777 Ranch in Hondo.  So, Halloween weekend in 1990 she gathered up her courage and drove to the hill country of Texas.

Upon arriving at the 777 Lodge, she was warmly greeted and shown to her room.  Her guide for the weekend was patient, respectful and very encouraging to this “Newby”.  They drove all over the ranch looking for the Blackbuck and of course saw everything but.  The few Blackbuck they did see were not within shooting distance.   As the day began to wane they spotted a buck a the top of a sendero at about 300 yards.  When her guide asked if she wanted to take this buck she said sure, but tell me what to do.  She had no idea about distance, wind, uphill, etc.  All she knew was how to hit the bulls eye.  The buck was standing broadside and her guide told her where to put the cross hairs.  Dr. Price did as she was told, and squeezed off the shot and the buck collapsed.  She started shaking so badly she could not move.  She sat down and tears began falling.  Dr. Price had done something she had dreamed about since she was a child.  She was now a hunter.

Dr. Price completed the weekend with 2 other critters, a Russian boar and a Axis deer.  Look out Africa, here she comes!!

Dr. Price has been fortunate to go on many hunts since that fall weekend and hopes to have many more opportunities.  She went back to South Africa in July 2009 for a Leopard.  She has decided that she might as well just do it.  She might even be looking for an elk hunt or maybe Yukon moose and oh yes a……!

Dr. Price says, “Thank you, Bill Weiss and Dallas Safari Club for giving me the opportunity to fulfill my dream.”  

And when Dr. Price is  not hunting….we have her working at the Center.

Dr. Price is one of the leading Audiologists in the nation.  She founded Hearing Professional Center in 1983 serving the diagnostic and rehabilitative needs of over 40,000 individuals.

Dr. Price serves as Chair of the Audiology Foundation of America, Children’s Medical Center Trustee, Chair of Children’s Medical Center Injury Prevention Initiative, in addition to serving on the Head Start Health Services Advisory Committee.   Since 1986 she has provided hearing conservation education, ear plugs and hearing testing for Dallas Safari Club, Texas Big Horn Society and Women Shooting Sports as a Life Member.

Over the past 30 years, Dr. Price has donated countless hours, 400 hearing aids, 200,000 batteries, and more that $60,000 in medical equipment to benefit low-income hearing impaired children and adults.  She founded Deaf Services International in 1986 for children in Mexico.  She worked with the Rio Negro Foundation in 2003 to test and treat natives along the Amazon River.  Dr. Price says, “I entered this profession to help improve lives through better hearing and better hearing protection.  I want to continue helping others, particularly those who cannot afford hearing aids.”

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Now Hear this…. Are You at Risk for a Hearing Loss?

June 18th, 2010

By: Bettie Borton, Au.D., FAAA
Doctor of Audiology
Doctors Hearing Clinic
7025 Halcyon Park, Suite A
Montgomery, AL 36117
(334) 396-1635
www.doctorshearingclinic.com

Did you know hearing loss…

  • Is the third most prevalent chronic health condition in America, behind high blood pressure and arthritis?
  • Affects 36 million Americans (about 17% of adults)?
  • Is more common in men than women?
  • Costs our economy billions of dollars in lost wages and hidden costs annually?

Is not being adequately identified by healthcare professionals? Only 38 percent of adults ages 70 years and older and only 29 percent of adults ages 20 to 69 have had their hearing tested within the last 5 years!

Do you or someone you love have a hearing loss? If so, you’re not alone. Almost 20% of adults in the United States will develop hearing loss during the course of their lives, and if undiagnosed and untreated, its affects can be devastating. Impaired hearing can have a profound impact on emotional, physical, economic, and social well-being.  People with hearing loss have documented decrease in quality of life, reporting symptoms of depression, dissatisfaction with life, reduced functional health, and social isolation. Statistically, they have lower income levels, and frequently complain of frustration in relationships and various communicative situations, as well as inability to enjoy social situations, and fatigue. Despite the fact that most people with hearing loss can be helped with today’s state of the art amplification, many never seek help, or resist the use hearing aids or other assistive listening technologies.

The causes of hearing loss are varied and resultant impact on auditory capability may range from mild to pronounced. Sometimes the cause or etiology, such as wax build up in the external ear canal or an ear infection, is readily apparent. In other instances, the cause of hearing loss may be more obscure. Decreased hearing is often called “the invisible handicap”. Because hearing impairment (especially loss related to aging) often presents very gradually, those with significant hearing impairment can be unaware of their loss. Family members, significant others, co-workers and friends are frequently the first to notice communication problems related to decreased hearing sensitivity.

Given that 36 million Americans are faced with this “invisible handicap” what kinds of risk factors increase the likelihood that someone will develop hearing loss? Why do some people develop hearing loss and while others do not? Some risk factors are obvious, but others are much more obscure.

Perhaps the most widely recognized risk factor is aging. Presbycusis, or the loss of hearing that gradually occurs as we grow older, is a familiar scenario for those of us with older family members. In fact, about 30-35 percent of adults between the ages of 65 and 75 years have a hearing loss, while an estimated 40-50 percent of people 75 and older have a hearing impairment.

Loss associated with presbycusis is usually greater for high-pitched sounds, resulting in the frequent comment “I can hear people talking, but can’t understand them clearly”. It is most commonly binaural (in both ears), affecting the ears equally. Because this type of loss in hearing sensitivity is so gradual, people who have presbycusis frequently lose their frame of reference for normal loudness of sounds, and often do not realize that their hearing acuity is diminishing.

The resultant relationship dynamic is frequently the subject of jokes – “My husband suffers from ‘selective’ hearing and he’s driving me crazy”! In reality, however, hearing impairment is no laughing matter and can take quite a toll on communication with significant others. Research indicates that for couples where one person has unaddressed hearing loss, the divorce rate is actually significantly higher.

Most people would agree that we now live in a very noisy world. Noise levels for rock concerts, radios, motorcycles, traffic, industrial and lawn equipment, and even our personal listening devices constantly bombard our auditory system. It is not surprising that noise exposure is another one of the most frequently cited risk factors for hearing loss, and now rivals aging as the number one cause of hearing loss in this country.  Noise from occupational, recreational and sporting activities all pose significant hazards to hearing in the United States today. Firearm use is one of the biggest culprits in our area of the country. A single shot from a shotgun, experienced at close range, can permanently damage hearing.  Repeated exposures to loud machinery in the work place or as part of yard maintenance or recreational experience may, over an extended period of time, present a serious risk to hearing. Even something as seemingly benign as blow dryers for styling hair put hearing at risk.

Consider the noise levels for such activities as NASCAR, jet ski and power boat usage, and lawn equipment. The cumulative effects of these noise hazards and many others pose a serious risk for hearing. Noise exposure risk is a time weighted function – in other words, the longer the exposure time, the greater the risk, and lower the loudness level required to cause damage. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), 10 million Americans have already suffered irreversible hearing damage from noise, and 30 million more are exposed to dangerous noise levels each day. A one-time exposure to hazardous noise resultant from gunfire or a rock concert, no matter how brief the time, of 120 dB or more can leave hearing permanently impaired. Prolonged exposure to only 85 dB (which can be generated by a commonly used appliance such as a blow dryer or hand held power tool) can do the same. 

Children and young adults are bombarded with potentially damaging noise exposure, most of which is easy to overlook. Most people intuitively recognize that “boom boxes”  IPODS, and other personal listening devices, if played too loudly, constitute a risk to hearing. However, consider the noise levels inherent to playing in a school band or orchestra. Students engaged in this commonplace activity spend hours practice in noisy environments within the context of their academic activities, yet many of them are not wearing appropriate ear protection, nor are schools effectively addressing this problem. To complicate matters, for reasons that are not fully understood some people are more susceptible to noise exposure than others.  As an example, research indicates that those with blue eyes are more prone to noise exposure than those with darker eye color!

Aging and noise exposure are two rather obvious risk factors for hearing loss, but there are many other factors that are more insidious. Studies suggest that there is a strong genetic component inherent to hearing loss, both for childhood deafness as well as presbycusic loss. If your parent or grandparent had hearing loss, your risk factor for developing a similar impairment may increase. If you had a relative who was hearing impaired from birth, family members of child bearing age need to be mindful of this risk factor, and be particularly vigilant with regard to insuring that the newest members of the family are effectively screened at birth for hearing sensitivity.

Various diseases of the ear certainly pose risk to hearing sensitivity. Ear infection, otosclerosis (a bony growth in the middle ear cavity), Meniere’s Disease, acoustic neuroma (a tumor on the auditory nerve), and a host of other maladies are obvious risk factors for hearing loss. But did you know that hearing loss is about twice as common in adults with diabetes compared to those who do not have the disease, according to a new study funded by the National Institutes of Health (NIH)? Visual deficits have long been associated with diabetes, but hearing loss is an under-recognized complication. Because of the strong correlation between diabetes and hearing loss, The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), recently suggested that people with diabetes should consider having their hearing tested.

Use of common drugs such as antibiotics, aspirin, diuretics and chemotherapy can cause hearing loss. Typically, hearing loss from ototoxic drugs is high frequency, which often results in the hearing impairment less obvious to those it affects. All radiation and chemotherapy patients should insist on baseline hearing assessments before, during, and following their course of treatment to insure that auditory effects of ototoxic interventional strategies are carefully monitored and treated.

Race and gender also play a role in hearing loss risk factor determination. Researchers now know that compared to women, men are five and one half times more likely to have hearing loss. White and Mexican American men have a higher incidence of both high-frequency hearing loss and hearing loss in both ears than blacks, who were 70 percent less likely than white participants to present with hearing loss.

With the dramatic increase in airbag use, motor vehicle accidents (MVA’s) are common culprits for increased risk of hearing loss. In fact, 17% of those involved in MVA’s with airbag deployment will have permanent loss of hearing as a result. Other insidious risk factors for hearing loss include smoking and cardiovascular disease. The incidence of hearing loss is significantly more pronounced among smokers, as well as those with any type of cardiovascular disease.

Many healthcare professionals simply don’t make these associations, and as a result, do not refer patients for hearing evaluation as often as risk factors might dictate. So, the message is be aware, and be proactive in assessing your risk, or that of your loved one, for hearing loss. For a comprehensive audiometric evaluation, see a Board Certified Doctor of Audiology. If you’ve never had a baseline audiogram, it’s certainly in your best interest to do so. Only 38 percent of adults ages 70 years and older and only 29 percent of adults ages 20 to 69 have had their hearing tested within the last 5 years.   If you’re over 65, hearing evaluation each year by a Board Certified Audiologist should become part of your annual medical maintenance program.
(Sources: BHI, NIDCD, ABA)

Dr. Bettie Borton is a Board Certified Doctor of Audiology, and a nationally recognized expert in hearing healthcare. She has more than 30 years’ experience diagnosing and treating hearing impairment in children and adults. Dr. Borton has served as the President of the Alabama Academy of Audiology, National Chair of the American Board of Audiology, and currently serves on the National Board of Directors for the American Academy of Audiology.

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Tinnitus: What’s that ringing in my ears?!

May 21st, 2010

By Shannon M. Aiello, Au.D., CCC-A, FAAA
Doctor of Audiology
Directory of Audiology
Columbia Basin Hearing Center
1149 N. Edison Street, Suite D
Kennewick, WA 99336
(509) 736-4005
www.columbiabasinhearing.com  

What do David Letterman, Pete Townshend, Charles Darwin, Ludwig Van Beethoven, and Steve Martin have in common? Other than being notable individuals in history or entertainment, all of these people have lived with chronic tinnitus. And they are not alone. The American Tinnitus Association estimates that over 50 million Americans experience tinnitus. Of these, 12 million have tinnitus that is severe enough that they seek medical attention. Furthermore, approximately 2 million persons have tinnitus that is so debilitating they cannot function in their daily lives.

Tinnitus is defined as the perception of sound when no external sound is present. Tinnitus is often referred to as “ringing in the ears,” although some people hear hissing, roaring, whistling, chirping, or clicking. It can be intermittent or constant, with single or changing frequencies.Because there are so many causes of tinnitus, it is important to be thoroughly evaluated to determine what exactly is causing the ringing. Many times people are told that tinnitus is normal with aging or that they just have to live with it. This is an untrue statement. If there is a medical issue causing the tinnitus often times, when it is treated the tinnitus may subside. Although there are very few treatments for tinnitus available, it is important that people with tinnitus understand where it is coming from, what to do if it gets worse, and what they can do to successfully manage their tinnitus.

Hearing loss and noise exposure is the most typical cause of tinnitus. For these patients, the tinnitus is typically permanent. Because of the vast number of people that suffer tinnitus, there are many companies that are trying to capitalize on this condition by advertising various herbal supplements or devices to help stop the ringing. Sadly, many of these supplements and “treatments” are extremely overpriced and have not been shown clinically to reduce the perception of tinnitus.

There are however, different options available for tinnitus suffers to help reduced their awareness of the tinnitus. For those who have hearing loss in addition to tinnitus, if the hearing loss is corrected through the use of hearing aids the majority of people also notice a reduction, or complete cessation, of their tinnitus.

At Columbia Basin Hearing and Balance Center, we understand that tinnitus is a complex problem which is different with each patient. Because of this we take the time to understand what our patients are experiencing, do comprehensive testing to determine where the tinnitus is coming from, and speak extensively about individualized management, therapies, and options that may help relieve the tinnitus. We are actively pursuing and using new therapies and management strategies to help out patients experience relief from their tinnitus.

If you or your loved one has been told to learn to live with tinnitus, please contact one of our local Doctor of Audiology for the latest in testing and management of tinnitus. General information on tinnitus can be found at Columbia Basin Hearing and the American Tinnitus Association.

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Posted in Audiologist, Clinical Audiologist, Columbia Basin Hearing & Balance Center, Doctor of Audiology, Hearing Aids, Hearing Loss, Noise-induced, Ringing in the Ears, tinnitus, Uncategorized

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