Denver resident Carolyn Haas recently wrote an interesting essay describing her special needs as she is both visually impaired and has progressive hearing loss. Although some of her technical jargon usage is a bit off, she provides a detailed explanation on why compression can be bad; and is an interesting addendum as to why some people need a linear hearing aid response, beyond the need for speech envelope preservation. Here is her story:
…At age 23, I became a binaural hearing aid user. By then (the early 1980s), there were in-the-ear hearing aids and even directional microphones, so I could keep my hearing aids a secret. I still wasn’t fully accepting my hearing loss and its impact, often to my own detriment. It took a very long time for me to truly appreciate the importance of openly acknowledging my hearing issues and the need to take advantage of the amazing emerging technology that could help people like me cope with it more successfully. As technology improved, there were digital and programmable hearing aids. We now have the added capability of using Bluetooth for connecting to streamers, other assistive listening devices and even directly to our smartphones.
Today, some sounds are amplified while using compression and masking to keep other sounds in the background. For some, this is a mixed blessing. Having grown up with analog hearing aids, I am more comfortable with unaltered sound. As a blind traveler, I need all the input I can get to be oriented in buildings and on streets. Even the ambient sounds in a room and bouncing off of the walls can provide good information about room size and density. When walking outdoors, being able to hear the direction and flow of traffic is critical to being able to cross streets independently. Even more critical is full awareness of what is happening when there are the sounds of trucks squealing, horns blaring, sirens howling and construction machinery revving and beeping.
Most people would prefer not to hear these sounds and certainly not at full volume. The good news is that hearing aids have a built-in element called automatic gain control (AGC). This means that the sounds that are particularly loud and could potentially damage remaining hearing ability can be automatically squelched. Those sounds can be made softer, or they may even cause the hearing aid to briefly cut out all sound. This is not good for a blind person relying on hearing to navigate safely. In situations like mine, a blind hearing aid user may have a program in which AGC is turned off, allowing a more complete sound spectrum. In the interest of hearing preservation, audiologists who haven’t worked with a blind person might understandably be hesitant to do this.
Read the rest of Carolyn Haas’ story here.