Re: Tinnitus and a dip in the audiogram

[Johannes Käsbach <johk@xxxxxxxxxxxxxx>]

sorry, maybe a bit late now, but I wanted to post it (just saw that it was not sent yet ;))

Dear Kevin and Mark,

I find your discussion extremely interesting. I am having a slight tinnitus as well and am asking myself questions like yours ever since. Even though I am not researching in tinnitus, I am personally interested in any discussion in that field. By adding shortly my own experience, I hope to get some further interesting and helpful input from you and the auditory list.

I have a tinnitus in my left ear since 7 years. Both my audiograms (I made many during the years in different labs and they are all similar) show a completely normal hearing and do not indicate any kind of hearing loss. If I have to point out a dip that would be at 4kHz for my left ear at +10dB (all other frequencies are in the range of -5 to 5 dB). But this dip could have been there even before my tinnitus because I was playing violin for 10 years...
My tinnitus is just audible in absolute quiet environments (or before going to bed), but I also do know the effect Kevin describes that I perceive my tinnitus in noisy environments (I like the expression of "environmental allergies" here). My tinnitus is mostly absent when waking up and becomes present due to tiredness in the evening.

I would like to add to your discussion the effect of hyperacusis which I personally find most annoying side effect of my tinnitus. The distortion added by the hyperacusis is at very high frequencies and can be very prominent, hence masking the sound. It is mostly caused by unpleasent (rough) sounds like for example clicking plates or ambulance sirens even at low levels. But there is a certain threshold in level (I have never determined it) which is necessary to produce this distortion. So I guess, the frequency region causing the distortion is the one that might be "damaged". In the beginning, I could also hear the tympanic reflex in my left ear in these cases. Experts recommended me to train to stand these loud sounds (not to overuse - of course with care - earplugs) and by doing so, shifting my threshold for loud sounds upwards. That helped for the tympanic reflex issue but still I can perceive the distortion at high frequencies. So far, I just excepted it, but am still wondering if that might go away at a point.

My questions would be: How is it possible to identify the frequency region in that the distortion, caused by hyperacusis, is audible? Can that be linked to the frequency region that causes the tinnitus? 

My tinnitus was initialized by an acoustic trauma and I always understood all this described above as a disturbance of the entire auditory pathway. I was always hoping that with special training and time the system can be to some extent readjusted in terms of which levels it can stand before distorting the sound. I can perceive the same distortion in my right ear, but for much louder sounds. So I understand this distortion as a normal phenomenon which is perceivable for everybody at a certain level.

Thanks and best wishes

Johannes

P.S.: I am also a fan of power-napping ;)! But in contrast to your experience, Kevin, my tinnitus is like blown away after the nap...

 Am Sep 9, 2012 um 6:55 AM schrieb Kevin Austin:

> Hi
> 
> This is very similar to a question that I discussed recently with a few people from this list. Not being in the field, I have difficulty framing the question. Sorry.
> 
> A hearing test -- the tones, tests hearing threshold. The hearing test I took used discrete frequencies and therefore the results have to be extracted from an interpolation. I was diagnosed with "mild" hearing loss in the 4kHz and 8kHz range, which is about 1 1/2 octaves below my 'main' tinnitus which is a sort of small tone cluster around 11-12 kHz. The level of my tinnitus varies rather quickly with where I am - environmental allergies?
> 
> When I listen to music / sounds at around 70 - 80dB, to me, my hearing appears to be relatively "flat". I am not aware of a [to me] large dip in the 4 - 10 kHz range when I am listening at normal levels. I do have some hearing loss as while I can perceive 11kHz, my 13kHz perception seems now to be almost nil. This I call hearing loss. The other range I consider to be masking of low level signals when my tinnitus is having a bad day, or a bad hour, or even a bad few minutes.
> 
> I consider my tinnitus to be an environmental allergic reaction as every once in a while the level drops almost completely away.
> 
> Asked how I determine such an 'absolute reference', I reply that I gently rub my fingers together and note how close my hand needs to be in order to hear the rubbing. At "quiet" times, for my right ear, this can be 20 cm or more away from my right ear. On bad days with high levels of tinnitus, this can be 3 - 5 cm. When I listen to music [as I use the same sound system and do not adjust the volume], there is little noticeable difference in louder passages. The differences I note, I attribute to masking.
> 
> FWIW, my tinnitus is highest just after waking up, almost regardless of the time of day or where I have been sleeping. [I power nap in my car -- not while driving, in my office, and ... sometimes in my classes.]
> 
> 
> Kevin
> 
> 
> 
> 
> On 2012, Sep 9, at 5:09 AM, Mark Fletcher wrote:
> 
>> Hello everyone,
>> 
>> I've noticed that tinnitus researchers often talk about the frequency of tinnitus being at a dip in the audiogram (in some people). It's then said that tinnitus, therefore, occurs at the frequency of a hearing loss. Even if I could be said to have an area of expertise, tinnitus research wouldn't be it, but it's certainly an area of interest for me and I am someone with tinnitus who has done several audiograms. On my audiogram there is a dip around the frequency of my tinnitus, but I suspect this dip is due to masking of the tone or warble used rather than necessarily being indicative of a hearing loss. I'd be very interested to know how people make the distinction between masking by tinnitus and a hearing loss.
>> 
>> Many thanks,
>> 
>> Mark Fletcher
>> Institute of Hearing Research, Nottingham