Having your hearing tested - observations

[A.S.]

I've mentioned before that I have my hearing tested every two or three years. It's painless and surprisingly, here in the UK a hearing test is free. It takes about ten minutes to perform. As the local health center was offering a walk-in hearing test last Saturday I popped in and took my turn.

The first point to make is that equipment is not standardised across the profession. This time, using a very new fancy test set, the highest test frequency was 8kHz - just an octave or so above tweeter roll-up in a typical hi-fi speaker and far below the '20kHz' quoted as the highest audio frequency. It seems that the hearing aid manufacturers (Philips etc.) consider that improving hearing acuity up to 8kHz or so dramatically improves intelligibility, with little benefit beyond that frequency. It was said that the very latest, state-of-the-art hearing aids pushed that upper cut-off to 12kHz or so at very considerable expense - perhaps GBP 7000 for a pair of aids. The acoustic benefits of the 8-12kHz band were said to be marginal.

My test was in a normal doctor's consulting room. There was no soundproofing, and the noise from passing cars/planes made it very difficult to hear quiet tones, especially in the lower frequencies due to acoustic masking. However, all was well and my next appointment is booked for twenty years hence. However, the previous test using different equipment in a rather quieter environment showed (as I recall) that my two ears were (very typically) not exactly matched around 8-12kHz. This test didn't expose any such issue due to the lower upper frequency bandwidth.

In discussion with the acoustician several points are noteworthy -

1. Don't hesitate to check the qualifications of the test technician. No qualifications are required to give a hearing test. This may introduce a degree of variability and uncertainty into the process

2. If you are really serious about accuracy, you have to test in an extremely quiet room or better still in a soundproofed box - this is available in the better clinics. If you don't the masking effect can introduce errors of 10db or more in your reported acuity in what we'd call the midrange and bass

3. Enquire how recently the equipment was calibrated and against what standard

4. Look for big deviations in the sensitivity/frequency graphical results. The test is not designed to tease out fractions of a dB of hearing performance. In my test the levels were dropped in steps of 6dB (half sound pressure) at the test frequencies and that's a very detectable level change

5. The frequencies are widely spaced and it may not be safe to interpolate hearing performance between these spot frequencies e.g. 1khz, 2kHz, 4kHz, 8kHz

6. Age inevitably reduces high frequency acuity but in normal, health (but old) ears that diminution in sensitivity is gradual and progressive with increasing frequency. Everyone above 50 or so - even living in the most remote jungle - will be many dBs down in sensitivity at the very highest frequencies and probably no 50 years old can hear above 15kHz at best

7. Extended high frequency performance beyond, say, 15kHz adds nothing to the enjoyment of music because the amount of energy above 15kHz in classical music is utterly insignificant. Admittedly with pop music (esp. featuring electronic instruments) there could be significant energy above 15kHz but is it musical energy or just noise?

8. Our ears are quite unique and no two individuals will have the same hearing. Even between twins, where one has been exposed to loud noise there will be a measured impact on acuity

9. IF YOUR EARS RING WHEN EXPOSED TO LOUD NOISE YOU ARE MOST LIKELY DAMAGING THEM

10. It is your duty and responsibility to look after your ears. Surgery is not possible on the ear to restore hearing acuity. If in doubt protect your ears

Here's a question: In the countryside here middle aged farmers seek a hearing test complaining that others are mumbling - a sure sign of hearing damage. The acoustician can tell from the hearing test whether the farmer is left or right handed. How?

[hifi_dave]

Because he cups his ear using the right or left hand.

Either that or he picks out the wax using his favoured hand !!!

[EricW]

Here's a question: In the countryside here middle aged farmers seek a hearing test complaining that others are mumbling - a sure sign of hearing damage. The acoustician can tell from the hearing test whether the farmer is left or right handed. How?

My guess - hearing acuity will be less in the ear on the same side as the dominant hand, since any tools or equipment used with that hand will be closer to the ear on the dominant hand side.

[A.S.]

Almost.

Here is a clue

What do you now think?

[A.S.]

My guess - hearing acuity will be less in the ear on the same side as the dominant hand, since any tools or equipment used with that hand will be closer to the ear on the dominant hand side.

Most farmers (as indeed most people) are right handed. As shown in my photo, they would fire their shotguns from a position on the right side of their head.

So, which ear would show most signs of hearing damage then?

[A.S.]

Answer: their left ear. The one furthest away from the gun.

[EricW]

Answer: their left ear. The one furthest away from the gun.

My first reaction was "that's counterintuitive." Thinking about it a bit, however, I wonder if this could be because the actual sound of the blast emanates from the end of the barrel, and the right ear (for a right-handed shooter) is better shielded than the left?

[Sebastien]

I'm wondering, like with our hand and foot, if we have a dominant ear. Do we?

Sébastien

[A. E.]

I'm wondering, like with our hand and foot, if we have a dominant ear. Do we?

Sébastien

a study performed in Ataturk University/Turkey (held on 36 boy and 34 girl college students) says that ears are dominant at the same side with hands. {Turkiye Klinikleri J Med Sci 2007, 27:317-320}

[A. E.]

My first reaction was "that's counterintuitive." Thinking about it a bit, however, I wonder if this could be because the actual sound of the blast emanates from the end of the barrel, and the right ear (for a right-handed shooter) is better shielded than the left?

interestingly hearing lost occurs in the ear furthest away from the gun, rifle butt protects that ear in a way... if you don't wear ear plug or muffs properly in a noisy place, that ear is damaged though...

[Sebastien]

a study performed in Ataturk University/Turkey (held on 36 boy and 34 girl college students) says that ears are dominant at the same side with hands. {Turkiye Klinikleri J Med Sci 2007, 27:317-320}

An interesting point is that what I believe to be my dominant ear is the left one but my dominant hand is my right one.

Sébastien

[A. E.]

An interesting point is that what I believe to be my dominant ear is the left one but my dominant hand is my right one.

Sébastien

I've tested by myself:
I can use my both hands and feet but mainly right ones;
when I try to look with one eye, I close my right eye spontaneously, but when I look through viewfinder I close my left eye and use my right eye, and also my each eye sees the colors a bit different;
when I'm eating I chew on the right side mostly;
when I'm talking on the phone it's almost always on the right side.

I feel mostly my right ear pays attention to the coming sound from one point. Audiographic tests on my both ears (between 125Hz and 8kHz) show no difference, they are both ok. When I change L and R channels I don't hear any change in the sound quality, it disturbs me to hear the some sounds on the opposite side if I had listen it before.

In that study (I've read the whole article now) Dane et al. first performed several tests to see which side is dominant for each test subject, then they used a diapason (bone and air transmission) to see the hearing duration on both ears.