Hearing; balance and high frequencies
Your ears, like most of ours as we age, tend to show degradation at the extreme upper frequencies*. Those frequencies are only containing the harmonics of the instruments and it's the harmonics that add the 'sheen' or sparkle to the tone. But the fundamental tones themselves are at perhaps only a tenth (or even just a hundredth) of those upper frequencies. Providing that in the middle or presence frequencies (around 1kHz) your ears are well balanced, the fact that you can hear nothing at ten times that frequency will have no impact at all on your perception of a solid mono image on normal speech or music.
Originally Posted by Labarum
* Why are extreme frequencies more effected than others with age? It's the same problem with stiffness in the joints or muscles with age; the tiny cells that actually sense sound in the ear become stiff and they won't flex as easily, so the fast high-frequency tones just don't make them wobble. And no wobbling means no electrical signal is sent to the brain. The attached picture shows the actual hair cells that convert sound into electrical stimuli. In this patient, there is a shocking contrast between the fairly normal hair cells along the upper ridge (even they are not perfect) and the stumps of cells lower down. This is a classic case of excessive loudness. When those little cells are cut down like trees, they cannot regrow. Sadly, the patient will be deaf for life.
For this reason, I will not be drawn into discussions about how loud our speakers can play, because we have a social responsibility to our users. I have never measured peak loudness because I have respect for my own ears and I design for a full, warm natural sound when listened at a very reasonable listening level. Others design their speakers to be hammered into producing terrifying loudness.
I'm convinced that the most pertinent question a would-be speaker buyer should ask of the manufacturer is this .... "What loudness level did you design these speakers to be played at, to sound natural and life-like?' Here are some possible answers and what I'd suggest in response:
- Answer: "They'll play as loud as you like. The louder the better!" Verdict: Run a mile
- Answer: "About 10 on your amplifier volume control". Verdict: They didn't understand the question/are idiots
- Answer: "Er .... wot? Can you repeat the question ...". Verdict: Run a mile
- Answer: "About xx-yydB, which audiologists consider a safe listening exposure level for long-term listening". Verdict: these people are worth considering
Then you ask then what xx-yydB actually is. (Do a search for WHO hearing recommendations etc. etc.)
Alan A. Shaw
Harbeth Audio UK