Hearing distortion as opposed to volume loss

When one goes to an audiologist for a hearing test, does the audiologist test for amount and type of distortion as opposed to just loss of volume? If so, what is this test called and how does it appear in the audiological evaluation sheet given to the patient? If not, is it possible to distinguish between loss of volume and distortion as to the cause of hearing problems?

I am a music lover, have owned good stereo equipment in the past and want to purchase more. I wear HA’s in normal situations but usually not at classical music concerts and operas; I just try to sit in the first eight rows. And I never wore HA’s when listening to music on my stereo equipment. As far as I can tell, there is no distortion. A friend has suggested that I not spend much money on the equipment because of my hearing loss which is mild to severe in one ear and mild to profound in the other. He feels that because of hearing distortion I am wasting my money. On the other hand, years ago when I first became aware of my hearing loss, when I asked a hearing specialist about my audio hobby, he told me just to raise the volume.

In short, is distortion (as opposed to volume loss) one of the problems the average hearing challenged person faces? And if so, how is it measured if at all?

Distortion of music could come from damaged hearing nerves etc or from interaction of the music with the hearing aid software.

At any frequency where the hearing loss is under about 55 dB.HL the ear’s amplifier array is probably the cause. In this case a volume increase could help greatly, without loss of quality

However at 55+dB.HL then we may be seeing damage to the microphone array in the ear. Such damage can lead to distortion in the hearing process. There is no clear workaround for this.

To listen to music you might need a ‘music program’ where many of the aid’s fancy speech enhancement, noise reduction and feedback control features are turned off or at least turned down.

However if the musical notes you need are at frequencies which have losses way more than 55dB.HL then you should expect the music to sound less good than prior to your hearing loss.

From my personal experience I think you could get by buying less expensive stereo equipment because you probably can’t hear everything that the high end stuff offers. When I was in high school a lot of my friends were buying good stereo equipment and telling me how much better it sounded and I was unable to tell the difference between a cheaper system and a really good system. Then I worked with a guy who had spent over $60,000 on a super high end stereo system and insisted I come and listen to it and once I did it didn’t sound that much better than the stereo systems I had been listening to and this guy couldn’t believe I couldn’t tell the difference. I had to explain to him I had a inherited HF hearing loss and to me it just didn’t sound really any better and because of the hearing loss I was able to save the money he was forced into spending to satisfy his love for music. I will say that since I got HA and have a music program in them I find that music does indeed sound a lot better and I have found that some songs have lyrics that I did’t know they had, so maybe his super stereo system would have sounded better if I had HA back then, who knows!

Thank you for your prompt reply. If the distortion is there, how does it manifest itself? Does it smear sounds, make the volume uneven, ring, etc.? And how noticeable is it?

Only one or two musical instruments go above 2000 cycles, the violin being the most obvious. And, obviously, those musical instrument frequency charts don’t take overtones into consideration, I would guess. But I wonder how much music is lost if one’s hearing loss is only 55 decibels at 2000 cycles (not considering the lower volume.)

When I listen without hearing aids but with good high end head phones and acceptable volume, I am very satisfied with the sound. I play well recorded cds some of which I have listened to on extremely good equipment for over 25 years and even before on LP (same performance, same recording.) Although one might say that auditory memory can be tricky, it seems to me that the sound over the headphones is close to what I used to hear over good speakers, etc. Shouldn’t this suggest that I am not bothered by obvious distortion?

And when I listen to music in a concert hall close up and without HA’s, I do not notice any distortion. I just do not hear soft sounds or one or two instruments at times such as the triangle, at least that is my guess.

What really bothers me is that if there is distortion in my hearing, it does not seem that this distortion is easily measurable or is not measured separately during the usual hearing test. At least I see no mention of it in my various audiological evaluations done in at least two different hearing centers over a period of years.

If music still sounds fine & distortion free, although needing to be played at a higher volume than in the past, then you are probably fine.

I suspect that you’ll notice distortion if & when it appears!

How would you measure it objectively though, you can’t hook-up your cochlea to an oscilloscope and then compare the output to a sine wave input. The implication that you would get a fixed result in the form of a transfer function is flawed, due to the dynamic effect of the ‘cochlea-amplifier’.

The cochlea-amplifier is a brain/cochlea tuning system that uses bi-directional nerve transmission to sharpen the response of the basilar membrane to hear sound more clearly. Any part of this system may not be working as intended, which could result in a deficiency in your hearing. Once these issues become based on the auditory cortex, there isn’t a whole lot that can be done. Hearing aids may help to deliver better levels of sound at the start of the chain, but beyond that, you are into the realms of what certain drugs may or may not do. Barring other system dysfunctions like a neuroma, physical intervention is unlikely as the outcomes are never going to be improved in such a finely balanced system.

I always thought of the discrimination score as tangentially related to distortion.

It does assess the entire system performance, but you can understand a Dalek’s voice which is significantly distorted. Or to put it another way Hendrix vs John Williams guitar - you’d be able to follow the notes on either, but only one would be clipped/modified. How that relates to what you or I would discern as quality is a higher processing function.

Loud noises sound distorted to me, like a damaged speaker or a speaker turned up too loud. I went to the Auburn-Alabama game Saturday (War Eagle, “cough”) and at times the crowd noise is unbearable and distorted sounding. I don’t notice it unless the noise is very loud.