Digital Hearing Aid Innovations
Digital Hearing Aids in West Las Vegas, NV
One of the Top 25 Innovations in the Past 25 Years. Digital hearing aids ranked along with the Internet, cell phones and portable computers as having had a dramatic impact on everyday life, according to a recently released report by Cable News Network. Like other innovations on CNN’s top 25 list, including air bags and ATMs, hearing aids have clearly demonstrated their value to people in all walks of life.
Twenty-five years ago, the variety among hearing aids was slight. They were bulky instruments and required users to manipulate dials and other controls and provided only basic amplification of sounds. Today with modern digital technology they afford a high degree customization and precision in hearing instrument fitting. The digital revolution has made possible small sleek devices that perform exquisite signal processing.
Since the early 1990s when digital technology in hearing instruments first emerged – computer technology has progressively improved, allowing hearing aids to mimic the brain’s ability to focus on speech patterns and minimize non-speech patterns. This restores the ability to cope with speech-in-noise that has been devastating to persons with sensorineural hearing loss.
It is appropriate to use the term, “Artificial Intelligence” in describing this circuitry. It functions very similar to the brain’s natural ability to automatically detect and optimize speech while turning down the volume on distracting sounds. The best of the modern devices continually scan the environment for voices and other sounds and reacts instantly to variations in sound signals, making thousands of calculations per second. They make life more pleasant for persons with hearing loss to cope with environments such as a busy street, social gathering or crowded restaurant.
Improvements in Filtering Background Noise
No circuits exist in hearing aids that can totally remove noise and leave speech. However, directional microphones can accomplish that task to some degree. If the hearing aid does not have directional microphones or if the situation is such that the directional microphones will not help, the hearing aid itself cannot clean up a noisy signal on its own.These circuits work by removing the pitch ranges that seem to be dominated by noise. The problem is that speech covers the entire bandwidth of the hearing aid. If any pitch ranges are removed in order to remove noise, speech information will also be removed. This approach works particularly well for constant noises, such as a refrigerator running or the hum of a computer.
Now, if this removal is done with a gentler hand (meaning that the amount of reduction is limited), then the loudness or annoyance of the noise level can be reduced. You may not understand speech any better (since no new information is added to the signal), but you may find the response of the hearing aid to be more acceptable.
A newer approach is to reduce the amplification during times when no speech is present. This approach allows the ear to have a break when no one is talking but then restores the full signal when the speech starts again. The goal is that throughout the course of the day, the “fatigue” factor of using a hearing aid is reduced.