ANL stands for acceptable noise level, the sound level we can tolerate without complaint. The idea behind ANL is that many potential hearing aid wearers wont get fitted because some of todays devices still amplify across the full acoustic spectrum. So, background noise comes in loud and clear, along with the voice of your dining partner. Why bother with a hearing aid that just amplifies the problem?
Collecting the Information
Testing an individuals ANL, the patient first listens to a recorded story. Volume is set at the patients most comfortable listening level, or MCL. So, things are adjusted to the comfort levels of the test participants. So far so good.
But then, researchers add a new dimension to the listening experience by adding neutral, sonic wallpaper behind the ongoing story narration. Background noise levels (BNL), are set to the highest volume accepted by the listener.
The subjects ANL acceptable noise level is calculated as a number using the following equation: (For those who arent into equations, feel free to skip this section.)
Whats Your ANL?
Acceptable noise level is determined as follows:
MCL BNL = ANL
Most comfortable listening level minus background noise level equals acceptable noise level. Yes, it sounds like a lot of math but its a fairly simple calculation and an effective means of determining a persons ANL.
Whats the Point?
Actually, there are a couple of points. The first is to change the way hearing screenings have been conducted in the past - in a quiet setting under clinical conditions. This isnt how the world is, and audiologists need a means to test and measure hearing acuity in a noisy, real-world environment.
The second point: Are you a good candidate for a hearing aid?
Hence, two excellent benefits to having an ANL test done.
Hearing Aid Acceptance and ANL
Research continues on a cross section of men and women who use hearing aids regularly, occasionally and never, i.e., theyre tossed in some drawer. Can you endure a bit more science?
Participants were tested for pure tone average, or PTA, (the average of hearing sensitivity for the frequencies of 500, 1000, and 2000 Hz) along with factors such as age, education level, speech perception in noise and many other variables. This testing provided researchers with some interesting conclusions, according to a report reviewing ANL research by audiologist Melinda Freyaldenhoven, Ph.D., and published by Audiology Online. Test results revealed that acceptable noise level may, indeed, be related to hearing aid use.
The Testing of ANL Continues
University of Tennessee researchers in Knoxville continue to develop ANL testing as an effective means of determining the suitability of patient and hearing device. Using baseline ANL data, and slowly adding background noise, is a proficient means of identifying suitable candidates for fittings.
This three-minute test has the potential of saving the patient and the audiologist wasted time and money. The success rate in using ANL to identify who could be a better candidate for full-time hearing aid use and who would not, researchers demonstrate, comes in at an impressive 85%.
Think of it as try before you buy. Ask your audiologist to arrange for an ANL test to determine whether or not youre a good candidate for a modern, digital micro-computer that actually fits into the ear canal.
Better to know before plunking down a lot of money for something thatll only collect dust somewhere. Test your acceptable noise level and improve lifes quality one way or the other.