OAEs are generated by cochlear (inner ear) structures and assess outer hair cell function. The cochlea produces sounds that can be evoked by sound stimulation. These sounds are called emissions and these emissions can be measured by means of a probe placed in the ear canal. Emissions are thought to be produced by rhythmical contractions of the cochlear hair cells. In the cochlea, there are inner hair cells (IHC) and outer hair cells (OHC). The outer hair cells are the single most important contributor to OAE production

OAEs are elicited by the presentation of sound stimuli to the ear canal opening, which will activate the cochlea. There are four areas sound must travel through in order to generate OAEs: 1) external ear canal, 2) middle ear, 3) cochlea, 4) efferent auditory system. The presence of OAEs indicates normal cochlear function. OAEs are prevalent in those with normal functioning cochlea’s almost 100% of the time. The absence of OAEs warrants further audiologic evaluation and does not necessarily mean the cochlea is not functioning properly. There are many factors that may interfere with the acquisition of OAEs, including: poor probe fit, ear wax, middle ear infection or disorder, vernix (protective cover on newborns), etc. The presence of OAEs in the external canal is dependent on the integrity of the outer, middle and inner ear. Hearing thresholds cannot be predicted from OAEs. However, in the absence of an audiogram (hearing test), the OAEs offer important cochlear information.

Please feel free to contact me with any of your audiological inquiries, or to book a hearing evaluation.

There is a test called Otoacoustic Emission (OAE) testing will assess the integrity of the outer hair cells (OHC) function. OHCs are most at risk to the effects of noise. This quick testing will reveal insults to the OHCs before any hearing loss may be reflected on an audiogram. An individual can lose up to 40% of these hair cells before any loss in hearing sensitivity may be appears on an audiogram.

OAE testing is also helpful when dealing with complaints of noise induced tinnitus; particularly in the absence of any measurable hearing loss. Tinnitus is the perception of sounds in the ears or head without any external stimulation. Tinnitus is a common accompaniment to NIHL. Tinnitus is believed to arise due to the discrepancy of hair loss damage that is greater loss to the OHCs versus IHCs. Since noise attacks OHCs, it stands to reason that tinnitus would often result in cases of noise damage. OAE testing will reveal OHC damage that is at the root of tinnitus. For individuals wishing to proceed with a complaint of noise induced tinnitus, OAE testing may be there only objective means of proving damage.

Fact: It is believed that genetics may predispose some individuals to greater amounts of noise induced hearing loss than others. Individual variations should be kept in mind rather than simply looking at a criteria that would indicate specific amount of hearing loss.

Myth: Noise induced hearing loss is always sensory, affecting hair cells in the inner ear organ called the cochlea.

Fact: NIHL tends to be sensory in nature; however, an acoustic trauma can cause a disarticulation or breakage of the middle ear bones and/or a rupture of the tympanic membrane. Therefore, noise damage may present itself as a conductive (middle ear), mixed (middle ear and sensory) or a sensory/cochlear hearing loss.

Myth: Noise induced hearing loss results in demonstrable hearing loss that will be evident on the audiogram portion of the hearing test.

Fact: NIHL attacks the hearing cells (outer and inner hair cells) in the hearing organ, the cochlea. Loss of the outer hair cells can account for the first 60 dB HL of hearing loss. Once the inner hair cells are involved, the hearing loss can exceed this level. However, an individual can lose up to 40% of these hair cells before any loss in hearing sensitivity may be appears on an audiogram.

A test called Otoacoustic Emission (OAE) testing can assess the integrity of outer hair cell (OHC) function. This quick testing will reveal insults to the OHCs before any hearing loss may be reflected on an audiogram.

Myth: Scientific evidence indicates that previously noise-exposed ears are not more sensitive to future noise exposure and that hearing loss due to noise does not progress once the exposure to noise is discontinued.

Fact: Metabolic changes to the outer hair cells, due to noise damage, may result in a greater likelihood of erosion of the outer hair cells over time.

Resource: Lipscomb, David. Hearing Conservation.

When you have a hearing loss, it is as if you have been wearing earplugs. The volume of sound has been reduced due to your loss. When you begin to wear hearing aids, your auditory system may be sensitive to loud sounds. Your brain will have to learn how to hear again. Most hearing aid wearers require an adjustment period of a few weeks.

It is best to gradually introduce sound back into your environment. Modern hearing aids are equipped with loudness adaptation levels. As your brain adapts to increased auditory input, these loudness levels can gradually be turned up.

Tips for learning to use hearing aids:

1. At first, wear hearing aids in your own home environment
2. Start off with one-on-one conversations in quiet
3. Do not strain to catch every word
4. Do not be discouraged by background noise
5. Increase your tolerance for loud sounds slowly
6. Gradually extend the number of persons with whom you speak

Resource: www.audiologyonline.org

A telecoil is also useful anywhere there is an indication that a location has a “Loop System” for the hearing impaired. When a location is serviced by a Loop System, hearing aid wearers should turn their hearing aid to the setting marked “T”. In large reverberant areas, sound, music and speech will bounce of the walls, floor and furniture. This can cause the speech to be unintelligible. A telecoil will harness the auditory signals in these often challenging listening situations.

Loop systems can be utilized at home, by means of using magnetic energy to transmit a signal from a TV or PA system. By selecting hearing aids with telecoils whenever possible, audiologists are helping to maximize their patients’ listening experience in a variety of environments. While other ALDs (Assistive Listening Devices) exist, they are typically much more expensive than telecoils. It is also the role of audiologists to encourage the spread of hearing aid compatible Loop Systems wherever PA systems exist; such as churches, auditoriums, courts, theatres, airports, educational and convention facilities in order to provide a cost-effective, improved listening and communication experience for the hearing impaired population.

Resource: The Hearing Journal (May 2006)

The link between diabetes and hearing loss has been well-established. Recent studies (Frisina et al., 2006, Kakarlapudi et al., 2003) have supported the theory that diabetes prematurely ages the hearing system. These studies indicated a significantly higher prevalence of hearing loss among the diabetic population as compared to non-diabetics. Treating the diabetes itself is the best defense against hearing loss. In cases where the treatment of the diabetes is insufficient, a hearing aid can help to compensate for the hearing loss. Patients with diabetes should have their hearing assessed regularly to monitor their hearing status for any changes.

Feel free to contact me at (506) 857-3223 or 1-800-535-1000 for more information on this topic, with any other audiological inquiries or to book a hearing evaluation.

Resources:

Diabetes and Hearing Loss
Cunningham, Lisa and Lendra Friesen (March, 2006). Diabetes and Hearing Loss in Audiology Today.

Therefore, regular hearing evaluations are recommended to assess if the hearing loss has advanced to the point in which the present prescription of power in your hearing aids is no longer adequate.

Modern hearing aids are programmable and can often be reprogrammed to accommodate the progression of hearing loss. Some hearing aids are not programmable and were ordered with a power prescription that suited your loss when they were ordered. This prescription may no longer suit your degree of hearing loss.

Sometimes a patient may require a change to a larger style hearing aid in order to obtain the required increase in gain, or volume.

Another likely possibility is that the hearing aids may not be working optimally. Hearing aids are exposed to a rather inhospitable environment in your ear canal. There is moisture, dry skin and wax in the canal. These factors can cause the hearing aids to weaken over time.

An audiologist can assess both your hearing and the current status of your hearing aids. Recommendations can be made to you on how to best meet your hearing needs, based on the outcome of this session.

For further information on this topic, or with other audiological inquiries feel free to contact me at 857-3223 or Toll Free at 1-800-535-1000

A 2003 study conducted by Staller et al., confirmed these findings. The study indicated Cochlear Implantation in each ear improved the patient’s ability to localize sound, improved speech recognition in competing noise situations and showed great benefit for head shadow.

Studies have also shown patients who use bimodal stimulation (A cochlear implant in one ear and a hearing aid in the non-implanted ear) resulted in better speech benefits as well as localization abilities (Ching et al., 2004 & Seeber et al., 2004)

For further information on this topic, or with other audiological inquiries feel free to contact me at 857-3223 or Toll Free at 1-800-535-1000

A hearing aid should not be too tight or too loose as this would cause either discomfort, poor retention or poor performance. If the hearing aid is causing redness or irritation the audiologist should be contacted immediately. It may be possible to modify the shell of the aid or it may be necessary to have it remade to achieve a more comfortable fit.

A hearing aid that fits too loosely can cause poor retention and may even fall out of the ear. The solution for a poor fit is usually to remake the hearing aid. Most manufacturers will remake the aids at no charge during the first or second year of the warranty.

Please call your audiologist if the hearing aids are not fitting properly. In the case of poor fit causing redness, the aid should not be worn until the problem is remedied and the skin affected has healed.

Nerve deafness usually affects a person’s ability to hear high pitched sounds more than low pitch sounds. The person with this type of hearing loss may have trouble hearing the high pitch consonant sounds such as f, s, t, p, th and sh. They may complain that other mumble since they miss the high frequency parts of speech. Depending on the degree of the hearing loss, a person may be able to hear some sounds and not others. This can be confusing and frustrating.

Warning signs of a hearing loss may include

1. People often sound as if they are mumbling

2. You have to ask people to speak up or repeat

3. You find yourself turning one ear toward the speaker to hear better

4. Ringing in your ears

5. others complain that you speak too loudly

6. problem hearing in situations where there is background noise

7. others complain that your radio or TV volume is too loud

8. you can no longer hear your watch ticking, faucet drip, door bell or phone ring

If you are experiencing any of these symptoms, I would suggest you arrange to have a hearing test.