LHMAudio said:
Being 60+ years old, I have lost hearing above about 12kHz. I have searched this forum on this subject and there are many posts about hearing loss with age, but no apparent conclusions about the effect on speaker design.
The holy grail of audio seems to be flat response to 20kHz or beyond. But if hearing above 16kHz is very limited, do we need to design out to those limits? If I instead target flat response out to 15kHz won't my design task be easier, less costly but with equal sounding results?
Or are there artifacts or harmonics that are within my range of hearing that will be lost as well?
Lindsay
Lindsay, I too am an old fart at the young side of sixty, and have what is called bilateral high tone deafness. I am a combat veteran, and got my injury in the military. Too many tank guns and M-16's high pitch crack. Also, I use a compressor in my business, and I wear stereo headphones when I use my staple gun, because the noise of the gun's blade, striking the wood as it drives the staples into the wood, bothers me.
But just because you have a hearing disability does not mean that you are unable to pick up high frequency signals. Inside the inner ear, and also within the cochlea, are tiny hairs, called celia, which act as tuning forks for the different pitch of all sorts of frequencies. Every frequency has celia of certain length and thickness, which generate different frequencies. These frequencies are, in turn, amplified as they move up the auditory nerve to the brain.
As you experience age, or trauma due to loud noise, the celia of certain frequencies are damaged. Over time, they will shrivel up and die. Many, however, will not.That is why a hearing aid will be able to amplify a certain frequency, and you will still be able to hear it. And that is because some of those dedicated celia for that frequency are still functioning. If they were all dead, you would not be able to hear ANY frequency, even with amplification.
Today's digital hearing aids are becoming very sophisticated, in that the number of dedicated frequencies to amplify are increased. Today it is common to see digital hearing aids that have over fifteen or twenty different frequency stages. In a few years, it will be almost unlimited. Perhaps the future ones will be able to amplify sounds every ten cycles, who knows.
But the neat thing is that science is now hot on the trail to manipulating genes in certain animals and regrowing these celia. In other words, by regrowing a full crop of celia, you would be able to hear like you could as a child. And it may be possible to even tailor the celia to grow and pick up frequencies below or over what humans can naturally pick up. Amazing!
I am now at the point where I really should have hearing aids put in my ears. Fortunately the VA will provide them for me, and better yet, give me all the batteries I need, for the rest of my life.
As for hearing, you can still discern certain frequencies that you may not think you should. And with practice you can discriminate more than you could without practice. for instance I can definately tell differences with many of my receivers. My Marantz is about as mellow as you can believe. Yet my Bogen tube receiver, which I am using right now, has a most sublime sound, yet is is as clear as a bell, more so than my Sansui 2000X that I also use with my computer.
So while you may be a little bit challenged, you are not without ability. The best thing to do is shoot for the best, listen carefully, and enjoy the best quality you can provide. I would still try to create a set of loudspeakers that cover the entire spectrum, because chances are you can still hear some of it, and with hearing aids, the possibilities are even better. That's what I would do.
