Unlike a person's vision and wearing glasses or contacts, which is easy to determine if the objects and text are clear and legible: wearing hearing aids and determining or perceiving if the sounds and volume levels are correct is much more difficult.

Sound and speech are completely different in their composition and how we perceive them both. Sounds consist of pure-tones, (pure-tone sounds are pure musical tones) which are longer in duration, usually louder in volume and wonderfully mixed as when listening to music. Speech on the other hand is complex pure tones, which are short in

durations and are mixed into vowels and consonants sounds that become language

When a person has diminished hearing, the hearing loss is not linear in nature, it does not occur equally in all the pure-

tone frequencies. Most hearing losses are sensorineural inner ear hair cell damage) and occur in the higher trequencies

and these higher frequencies are what comprise (make-up) the consonant sounds of words. Therefore, the most common complaint for most hearing-impaired individuals is that they can hear the voice, but they cannot understand the words clearly. The reason they cannot understand speech clearly is because the high frequency hearing loss is not allowing them to hear the consonant sounds that make-up speech. When a person misses a high pitch consonant sound in a word, the low tone vowel sounds run together, which makes it sound like the person speaking is mumbling or not talking clearly. This distortion of speech is caused by a precipitous, high frequency hearing loss, which is usually sensorineural in nature. Most hearing losses are high frequency because of the high-pitched hair cells proximity in the cochlear (inner ear).

Most if not all hearing aids are originally set by the manufacturer to default settings that do not match or compensate for the precipitous high-frequency hearing loss of each individual person. The default settings are used to make the hearing aids sound louder, but these default settings will not make speech much clearer.

It is impossible for the manufacturer to correctly adjust the hearing aids in these higher settings, so instead of running the risk of setting the hearing aids too high or too low, the manufacturer uses an average setting. These average manufacturer settings can be off by as much as thirty to fifty percent from what is actually required for an individual's high-pitched hearing loss.

This is where taking advantage of our hearing aid professional, Mark Oyler, BC-HIS, ACA, experience, and expertise will enable you to receive the most benefit to hearing and understand speech clearer.

Contrary to widespread belief hearing aids are not a one size fits all amplifier. The physical fitting and programming vary greatly for each individual because everyone has different types and degree of hearing loss; different tolerance levels;

different likes and dislikes when it pertains to sound, speech and noise amplitication.

Unlike any other type of aid that is fitted and adjusted to the individual's impairment, the prescription for hearing aids is not written from the hearing test results; the prescription is written during the acoustical programming of the hearing aids with specially designed digital fitting instrumentation. The Real Ear Measure (REM) fitting instrumentation not only determines and writes the hearing aids prescription during the programming process, but it also verifies that the hearing aids are properly fit to the individual requirements to insure the best outcome and benefits.

Because of all the mitigating factors that go into properly fitting hearing aids, the digital instrumentation of Real Ear Measurement (REM) is used to help factor in all the unknown elements and their effects on the hearing aid fitting.

The type and degree of hearing loss is important to know, whether it is a sensorineural, conductive or mixed type loss.

Along with the size and shape of the external (auditory) ear canal, the tympanic membrane (eardrum) compliance or elasticity will dictate the degree of required frequency shaping, the gain level, the output ceiling and compression ratios requirements to ensure proper fit and to protect the remaining useable hearing of the patient.

If care is not taken during the fitting of hearing aids, there could be unforeseen risk and consequences to the patient's useable hearing. A hearing aid is just what the word says, it aids the useable hearing that remains as a result of the hearing loss.

All great hearing aid fittings start with a correctly fitted and coupled ear-tip to the external ear canal. All ear canals differ greatly in volume sizes, shapes, and impedance (eardrums resistance to movement) levels. When fitting a hearing aid to an ear canal, the ear canal becomes the sound chamber of the hearing aid.

If the ear-tip is not properly sized and fitted to the ear canal, then the hearing aid will not provide adequate volume to move or vibrate the eardrum to shape the high frequency consonant sound for speech clarity.

If there is not enough high frequency gain or volume in the ear canal, then a masking effect occurs where the low frequency sounds of the hearing aids are louder than the high frequency consonant sounds. When this masking effect occurs, the low tones cover up the high tones and speech is not made any clearer; only sound and noise is amplified. So, you end up with a noise amplifier in the ear and not a hearing aid, which clarifies speech. The only way to verify the many intricacies of a properly fitted hearing aid is with the prescription fitting of Real Ear Measurement (REM).