What type of hearing tests do you do before fitting a patient with hearing aids? When you conduct hearing tests, are you simply gathering conventional audiometric data or are you already thinking about specific hearing aid fitting problems you will face with this patient?
When I evaluate a new patient I am thinking about: (1) circuits and power levels, (2) precautions I need to take to avoid a disastrous fitting, and (3) demonstrations I need to give to prove the value of the hearing aids. The data from traditional audiometric tests are invaluable, but only part of a much bigger picture.
What I call the “get-acquainted speech test” takes about 2 minutes and is the time I spend talking to the patient (via the speech audiometer and earphones) when the person is first seated in the sound booth. I ask: “Can you hear me? Am I loud or soft?” I then have the patient repeat many types of words and sentences at various intensity levels (see Test Words below).
WHAT THE “GET-ACQUAINTED” TELLS US
The “get-acquainted speech test” is part fishing expedition and part test. I want to find the level where the patient hears best, but, just as important, I want to find out how poorly the patient hears if the sound is 10 dB to 15 dB less than the ideal level.
This “test” provides the information I need to give the patient a persuasive demonstration of the value of hearing aids. When I fit the aids I walk 10 or 15 feet away from the patient and ask the person to repeat words. I set the hearing aids so that the patient will have good word understanding with the aids and no word understanding without them. This type of black-and-white demonstration is only possible if I have already determined the level where the patient is unable to repeat words presented at a soft level.
When I talk to the patient via earphones, I'm also looking to see if this is an easy or difficult fitting. If adjustments on the speech audiometer quickly result in excellent word understanding, then this is probably going to be an easy fitting.
If several adjustments fail to quickly provide good word understanding, I've probably got my work cut out for me. In such a case I continue “fishing,” which means I try other tricks like talking closer to the microphone, speaking more slowly, using easier-to-understand words, adding or removing lip reading cues, and/or trying various frequency response settings.
These “tricks” help me assess the degree of impairment and make a prognosis. I'm looking to see if anything gives this patient half-way decent word understanding.
Patients with poor aided hearing ability are candidates for assistive listening devices, extra counseling, and lots of hand holding. They need to know how to get every ounce of function out of their residual hearing.
When you do an informal test and ask the patient to repeat words, you have many categories of words to work with. You also have the opportunity to turn a serious test into a game, e.g., “Say the word Budweiser, Miller, Coors, etc.”
Here are several types of test words:
* Spondaic words (cowboy, baseball, etc.) are marvelous test items, easy for the patient to hear and understand.
* Rhyme words (chair, pair, bear; gold, fold, sold) are useful if the patient has good hearing and you need to make the test more difficult.
* Tonality words (low pitch: blue, burn, etc.; high pitch: shape, teach, etc.) are helpful if you need to assess the patient's word-understanding ability in a specific tonal zone.
* Short sentences are great items and can be used to tailor the test to the patient's interests. For example, if you know your patient loves to shop, you can choose test sentences like, “Neiman-Marcus is having a sale.” If the patient is a sports fan, you might ask, “Who do you think is going to be in the Super Bowl?”
I do conventional hearing tests after the get-acquainted test and I use each test to get as much information as possible. I love the Speech Reception Threshold (SRT), which tells us the softest point at which the patient correctly repeats the words 50% of the time. When I give this wonderful little test I make notes on how well the patient hears above threshold and how poorly he/she hears below.
There are many inherent advantages of using words to evaluate a patient's hearing. For instance, you can analyze the type of errors the patients makes: If the test word is “blue” and the patient responds “flew,” the patient is missing a simple low-tone speech sound. You may need more gain in the low frequencies, less gain in the highs, or both.
When you ask the patient to repeat words, you also begin to establish a close working relationship with the patient. It is a very personal type of test. Patients stay motivated to work with you. Nobody goes to sleep.
Over the years, pure-tone tests tend to become very routine. The patient either hears or doesn't hear the test signal. Word tests are never static. The more you use these tests, the better you get at understanding how well or poorly the patient hears.