[JRace]

In fact he couldn't see what I was complaining about, as he saw routinely saw people with ears which did not track one another to a much greater extent than mine and this type and amount of variation in hearing response sensitivity was not at all uncommon. In fact precise tracking from one ear to another across the entire frequency test range was uncommon.

Your issue was not that your ears were not the same, but rather that it suddenly changed. Having non-symetrical thresholds of hearing is not going to cause soundstage/imaging shifiting (unless there is significant differences, ie 15dB+ at more than one frequency).

The brain adapts for changes between the ears, however when something changes suddenly (even just one specific freq) it can intially be very frustrating. With time the brain builds new correction factors.

We don't test above 8kHz as it has little effect in speech comprehension, which is the #1 reason people seek out assistance. Not to mention we could not do anything to help regardless of what we find.

Audiometers are calibrated to dB HL not SPL. Let me see if I can find the correction chart...
That and it would take a very long time to obtain thresholds at all frequencies.

[coke]

Here's how I hear.  The black dots are the results of my recent test.  I didn't take care of my ears when I was younger. Lots of guns without ear protection and a car stereo that was metered at over 140 dB.   Thankful I still have decent hearing. I'd like to know what I can hear above 8k but that's as high as the test goes. 

I assume the reason my left ear is worse is driving with windows down.

One things shocking to me is how common it is for people to be down 70dB or more on this test. 

[JRace]

COKE: if you shot guns without protection you are very lucky to still hear that good!

If your shooting was from a rifle that could explain the differences between your ears.

Here is a chart to show the differences between dB SPL and dB HL.

[coke]

I think the majority of it came from shotguns.  I guess the left ear would be angled more toward the sound than the right. 

[mlundy57]

I conducted a very unscientific test on my hearing at home. I downloaded a set of test tones from 20Hz to 20kHz. I set my stereo to a normal listening level then played back the test tones one at a time. At normal listening levels I was able to hear everything up to 14kHz. If I significantly increased the SPL levels I could hear the tones up to 16kHz but I would never play the stereo that loud because the lower frequencies would blast me out of the house.

The issue I have with hearing tests is that while I can hear single isolated frequencies just fine for the most part, I have a lot of trouble understanding speech or picking out specific instruments such as the bass when there is a lot of surrounding sound. "A lot" being relative. For instance I can usually understand vocals when accompanied by acoustic music but can rarely understand even half the lyrics of rock music unless the song is a ballad. But then with ballads the music is subdued. With movies I usually have to pump the center channel way up to understand the dialogue.

I have recently found speakers that overcome, to differing degrees, this forest for the trees issue I have and the solution isn't so much with the absolute flatness of the response but with the separation of the response (space between the notes if you will).

Mike   

[stereocilia]

I conducted a very unscientific test on my hearing at home. I downloaded a set of test tones from 20Hz to 20kHz. I set my stereo to a normal listening level then played back the test tones one at a time. At normal listening levels I was able to hear everything up to 14kHz. If I significantly increased the SPL levels I could hear the tones up to 16kHz but I would never play the stereo that loud because the lower frequencies would blast me out of the house.

The issue I have with hearing tests is that while I can hear single isolated frequencies just fine for the most part, I have a lot of trouble understanding speech or picking out specific instruments such as the bass when there is a lot of surrounding sound. "A lot" being relative. For instance I can usually understand vocals when accompanied by acoustic music but can rarely understand even half the lyrics of rock music unless the song is a ballad. But then with ballads the music is subdued. With movies I usually have to pump the center channel way up to understand the dialogue.

I have recently found speakers that overcome, to differing degrees, this forest for the trees issue I have and the solution isn't so much with the absolute flatness of the response but with the separation of the response (space between the notes if you will).

Mike

That's definitely a limitation of pure tone testing.  You're absolutely right, it doesn't get to the more central (that is, closer to the central nervous system) dimensions of hearing.  The basic audiometric test battery includes a word-recognition task of words presented to each ear in quiet, and that reveals something about the overall distortion in the hearing system.  So, two people with exactly the same pure tone thresholds might have very different abilities to repeat single-syllable words back from a random list.  One person with a 40 dB flat loss might get 48% out of 50 words correct, another might get 100%.

The thing is, it's pretty rare to see people who have normal hearing thresholds from 250 to 8 KHz and poor word recognition in quiet at the same time.  Reliably testing for speech comprehension in noise gets trickier.  Trickier still is treating a problem hearing fine details in noise once it's been pinpointed.

On the topic of testing above 8 KHz, sometimes it's done to monitor the hearing of people who have to be on large doses of very specific and nasty antibiotics, or certain chemotherapy drugs.  Most ototoxic drugs tend to affect the highest frequencies first.  Often, though, the folks taking these don't have the option of decreasing the dosage even if changes in hearing do start to show up.