by Monica Duve Doctor of Audiology
Killean Audiology & Hearing Aid Centers
Anyone with hearing loss, or who knows someone with this problem, has heard the long running joke about “selective hearing”. I’ve certainly heard my own family members say such things as “dad hears when he wants to” or “whenever her husband talks, she doesn’t hear him – must be selective.” People with hearing loss often seem to communicate fine at times and seem to be totally oblivious to someone talking to them at other times. What is going on here? Hearing IS selective.
Hearing loss is usually partial. Like vision, there often is enough neural function remaining to “get by” in certain situations. For example, I can read without glasses so if all I ever did was sit in the house and read, I wouldn’t need correction. However, in select environments, like driving, vision correction is a must! The factors of distance and darkness really hinder my visual acuity in this situation. For those with hearing loss, factors such as room acoustics, visual cues, pitch of voice, amount of background noise, distance and many other variables affect how much of the signal reaches the impaired ear clearly. If conversations were always held in a small, sound treated room with a nice clear projecting voice (like mine) then hearing aids would be largely unnecessary.
Hearing aids are necessary, sophisticated sound processors, though. Why? Solving the problems of those with hearing loss requires so much more than making things louder. In fact, simple amplifying devices are inexpensive but do not offer much assistance to people because they amplify everything by the same amount. Thus, a basic hearing aid would turn up all the people mumbling in the restaurant, not just the person at the table we are trying to hear. This actually creates more hindrance when listening and it’s no wonder people wearing these types of devices are often not successful.
Modern hearing aids do so much more than amplify. A hearing aid’s job really is to scan the environment and decide which elect sounds or voices to clarify and which sounds to leave alone. All hearing aids have supercomputers in them now that scan the environment. This is called sampling and essentially means the hearing aids take a “read” of the levels and types of sounds in the environment. Hearing aids are constantly sampling at a rate of millions of times per second. Then, hearing aids needs to categorize all the sounds in the environment. So in the typical noisy restaurant, the hearing aid has to decide such hings as: what is near speech, what is far speech, where is the sound coming from, and what other sounds are in the room (i.e. echo, dishes). Then the hearing aids have to selectively enhance what is not in our rane of hearing and suppress the unwanted noise. Hearing aids do this all in real time and continuously as we move from environment to environment. Of course, there are different grades and prices of hearing aids depending on how accurate and effective the devices are.
Thus, the age-old joke of “selective hearing” is true!! But it’s not so much that “dad hears when he wants to”. Rather it is a matter of “dad” hearing well when all the conditions are just right and very controlled. Unfortunately, we do not live in a controlled world. With something as important as hearing, it is important to invest in hearing aids that can actually read and handle these difficult environments correctly. With the best recommendations and fit, listening becomes much easier, automatic and without the impression that we only listen when we want to. This holiday, isn’t it time that you took care of that hearing loss and quit letting others tease you about selective hearing! We offer free screenings and consultations. Come for a demonstration and find out what you are missing!