Let’s continue the story about distortion in hearing perception. You know, if you overload an amplifier, like in your audio system, it sounds awful. Well, with hearing loss, all the normal rules of hearing go out the window. The damaged inner ear can act like an overloaded amplifier.

It’s easy to measure how loud a sound has to be for you to detect it (pure tone audiogram). We tend to measure this with pure tones but this doesn’t tell anyone a lot about why you are finding it hard to hear in background noise. To hear clearly in background noise, your hearing system is using a lot of different functions. You are using the ear’s ability to detect sound and to code frequency and loudness. This can be a bit disrupted (distorted) at levels above threshold. You are also using the ears ability to detect minute changes in timing. This also gets disrupted.

You are also relying on thousands of nerve fibres being in good form to convey this information to the auditory cortex. Then you are using your auditory memory; you are using the nerve fibre and brains ability to process sound fast enough, and you are using your ability to attend. It’s complicated.

Sometimes when I’m out giving talks, which I do a lot, I meet people who can’t hear well in background noise, and they’ve been told this is “because of their brain”. I imagine they have been told that they have central auditory processing problems. It probably means they have a poor ability to discriminate speech sounds at raised levels, and especially in background noise. In practice, there are few clinicians who test for central auditory processing problems. The problem might lie in central auditory processing or cognitive capacity, but it is probably, at least, in part, due to coding issues in the inner ear and nerve pathways.

Personally, I don’t see the point in testing for central auditory processing issues, unless you are in a research environment. I rely on the researchers to enlighten us more on this topic. I think what we need to do as clinicians is find a workable solution for our clients. The explanation of the problem can be complicated. I fit hearing aids that keep sound in the “sweet spot” of hearing in 64 independent channels (frequency bands), to minimize distortion and hence to help in background noise, and I provide strategies to help. Lots of testing is only helpful if it is going to help with the solution. So we always do some form of speech in noise testing, with and without hearing aids, and we always try to give strategies to help.

If you get onto hearing loss early, you have a better chance of having an easier path to hearing well. If you have had hearing loss so long that you think you have left it too late, then don’t panic. Just set yourself for a longer time frame. Get excellent hearing aids (and hearing aids are not all the same) and approach it like training to get fitter. Send for My Hearing Plan from our website and get started planning today.