Hearing and Aging

[Mr. Widget]

I pulled this form another thread as I have been quite interested in the subject for sometime and thought it deserved it's own thread instead of derailing yet another thread with an Off Topic ramble.

A more serious question to me and possibly others is, As we age, Where does the human ear rool off?
I am sure we are all different in this respect but it is painful to not be able to hear what others apparently can.

I can hear fine, don't need a bionic ear to watch TV nor do I need it loud.

I just can't seem to hear this roll off. I can't hear my speaker wires. I can't hear any difference between $10 interconnect or $1000 ones.

Is it my ears or is there really people out here that have bionic ears and can really hear all these tweeks?

As with everything else in life aging is a function of genes and wear and tear. Typically females hear more acutely than males do. (But for some reason don't seem to get the audio bug like we do.) We do not all start out with the same level of hearing ability (more of the genes part) and as we age our hearing slowly degrades. If you are an avid hunter, a musician who played loud amplified music, or if you worked in a noisy machine shop or other noisy industrial environment you will very likely have damaged your hearing. (Accelerated the aging of them.) Here are guidelines for us to delay or reduce hearing loss. I took this from an Audiology website:

Preventing Presbycusis (Hearing Loss due to Aging)


If you don't have a hearing problem, taking the following steps may help reduce your chances of developing one. And if you already have presbycusis, following these guidelines may help you keep the problem from getting worse.

• Avoid loud or prolonged exposure to noise.
• When you can't avoid noise, wear ear protection.
• If your ears produce excessive earwax, have your ears cleaned periodically by a health care professional. (Do not use cotton swabs, as you will lodge more earwax even deeper into the ear canal than the small amount of wax you will remove.)
• Avoid ototoxic drugs. If you're taking one already, talk with your doctor and see if there's a less-ototoxic alternative.
• Stay healthy and be mindful of risk factors, such as hypertension.

How does our hearing roll off due to age?

Obviously it varies from individual to individual... but it typically starts up top and works down. At 18 I could hear a 20KHz sinewave... today at 47, I can barely hear a 16KHz sinewave.

Being able to hear TV, the telephone, and general speech intelligibility requires hearing up to about 5KHz... above that are only overtones and harmonics. They are incredibly valuable for flushing out the difference between different instruments and adding spatial ques and general "reality" to the music, but I suppose if you no longer hear them in live music, you won't miss them if they are lacking from your Hi-Fi.

Speaker cable, interconnects, and electronics? I have yet to hear a speaker cable that "improved" the sound. There are some that mess around with the sound, but good quality copper all sounds the same to me and to many of the people that I have talked to... some are of the "golden eared" set. Interconnects tend to have more of an impact, but even here... the clearly superior interconnect is rare. With both interconnects and speaker wire the quality of the connection is more important the the wire in between. Electronics do have a marked effect on the sound... simple high quality electronics tend to sound superior to heavily feature laden pieces of equipment.

Back on the subject of hearing and aging and anecdotal evidence...

I have had two older forum members over at my house at different times while I was testing tweeters. In both cases while taking an impedance measurement of the tweeters they were swept with sinewave pulses starting at 22KHz and sliding down the scale I heard nothing until the 16KHz frequency was pulsed. These two individuals heard nothing until below 10KHz... one first heard the signal at around 9.5KHz and the other around 9KHz.

Based on this info we might write off their hearing above 10KHz and think that they don't need a speaker that responds above that frequency. That was certainly my first thought. However as I have spent time with both of these individuals and talked about specific drivers, their sonic signatures, and simply what has worked and what hasn't... it has become apparent that they both did hear above the 10KHz point. The only conclusion that I could make was that with music as a source, we are able to hear higher frequencies than we do when listening to pure sinewaves.

Another anecdote:

I had my hearing tested not too long ago by a friend who is a pediatrician. She measured my hearing and was surprised to discover that I could not only pass the test at all frequencies (up to the 8KHz limit), but that my hearing was at the threshold of her machine... most of the children that she measures are not that good. I guess the years of my misspent youth blasting the hell out of several large JBL systems didn't hurt me too much.


Widget

[Titanium Dome]

As an add on to this topic, there's the problem of unilateral and asymmetrical hearing loss.

Unilateral hearing loss means that only one ear is affected.

Asymmetrical hearing loss means that the degree and/or configuration of the loss is different in each ear.

In my case, my right ear is the victim of unilateral hearing loss due to my brother's cute trick of throwing an M-80 into our outhouse when I was in there taking care of business. It exploded about 18 inches from my right ear, and the concussion took out a big chunk of hearing sensitivity that never returned.

This had the effect of ruining some spatial organization for me. For example, anytime I listen to headphones, the image is always shifted to the left, with the center at the 11:00 o'clock position in my head.

[Thom]

When you say at 47 you can hear a 16 khz sinewave you don't say how loud because if you hear well at 16khz you as a 47 year old mail you are the exception. I remember years ago many relationships I wittnesed suffer do to a noisy flyback transformer on an otherwise perfect tv that a wife could hear and a husband couldn't. Just under 16k if memory serves me. (often it doesn,t) Omn the rock concert thing studies have shown thad we find objectionable are more harmeful than loud sounds we find pleasurable.

[Steve Schell]

As recall, the frequency emitted by a TV flyback transformer is supposed to be 14,750Hz. This howl used to bother me with many sets, but I haven't heard it in several years now. When I first began messing with audio about 15 years ago I could hear up to about 17kHz., but now I hear nothing above 13.5kHz. when testing drivers with an audio generator. My upper hearing limit has decreased slowly but steadily over the years.

I think the averages of hearing acuity vs. age are made by sampling the public, most of whom have never learned to listen carefully. My hearing has been tested at several Piano Technicians Guild conventions and I always score well. That doggone Belltone hearing chart only extends to 8kHz. though. One audioologist mentioned that she found most piano technicians to have much better than average hearing for their ages. My theory is that we piano tuner types have developed the ability to isolate specific high frequencies at low levels from a complex sound field (required in piano tuning) and this gives us a perceptual advantage in these hearing tests. I would expect the same result with sesoned audiophiles.

One elderly horn enthusiast I know cannot hear any high frequencies; his limit may be only three or four kHz. When selecting crossover parts for his horn tweeters he uses midrange values, as he cannot hear any output from them using a more normal 5 or 7kHz. crossover point. He still greatly enjoys his constant fiddling with his system though, which I guess is the important thing.

[Ian Mackenzie]

I was testing a 3145 crossover the other night and with the slot connected I ran a 15.6 Khertz tone to set the L pads.

I could sense the tone and to me up there and above is something you sense. Its a bit like very low bass, it doesn't play a key role in normal music but it can add spacial cues. The same applies to so called Uhf, the fundermentals are quite audible, the overtones are sensed.

http://www.listenhear.co.uk/general_...htm#Percussion

Sound is air in motion — pushed, pulled, beaten, blown, plucked, talked, or sung into motion. Music is sound's highest achievement, a wonderfully varied mixture of patterned vibrations sent into the air by all kinds of instruments, from a cricket's hind legs to a massive pipe organ.

The frequencies of music, the various repetitions that make up the sound of instruments, are represented somewhat by the charts printed in equipment reviews in various audio/video magazines. But those charts look (and often are) so abstract that it's easy to forget that music is the point of it all. We are trying to remedy that here with the chart below, in which the frequency markings strung out along the bottom baseline are related to the frequency ranges shown above them of the various instruments in an orchestra.

If you've never had a chance to look at the way frequency response corresponds to the sound of instruments, you might want to note first that the divisions along the bottom line of our chart are anything but even. When most people first visualize the frequency range from 20 Hz to 20,000 Hz, they imagine a nice, linear, tape-measure span of measurement, on which the marked increments are as equal as the inch or centimeter markings on a ruler. But when you look at an actual response chart, the measures along the lateral line are definitely not an equal distance apart. In fact, the seemingly "small" span between 20Hz and 40 Hz is actually wider than the 6,000 Hz of difference between 10,000 and 16,000Hz. That's because the vibrations of the heavy-hitting bass instruments of music are ponderous and far apart, while the successively higher pitched instruments going up the scale vibrate faster and faster, and closer together. The frequency scale of music (and all sound) isn't linear but logarithmic — which is probably why mathematics and music often seem to go so well together.

Our chart, courtesy of Stereo Review, is fun. It will give you an idea (if you didn't have one already) of where musical instruments lie across the audible frequency range. And there are surprises. Who would have thought, if they hadn't already known, that the bottom of the harp's range went below a double bass's, or that the contrabassoon aced them both? Or that the top of the oboe's range edged out the soprano voice? Or that the piccolo's top note topped the violin's? Or that the same harp that went so low also went right up near the top of the violin's and piccolo's range? Or that the guitar's top note was under 1,000 Hz? Look around the chart for a bit, and we'll go further after that.

While the chart begins to provide a grasp of where instruments lie across the frequency range, it has some critical omissions. The pipe organ, for instance,which goes down into subterranean regions, isn't represented. Neither is the bass drum, which has lots of energy below 50 Hz. Most critically, however, the chart portrays only the fundamental tones that instruments generate. What it doesn't show is the overtones, the harmonic frequencies, that give instruments their characteristic sound — their timbre.

Harmonics are what let you tell instruments apart. Without them, similar instruments that played the same frequencies would sound the same. The harmonics are produced not by the notes, but by the method by which the musician sets those notes into motion and the materials used to produce the notes. The plucking of a string on a guitar, or the bowing of the string on a violin, is a lot different from the metallic resonance of a flute as air is blown through it by pursed lips, or the sound of a drum's membrane when it's struck by a hand or a drumstick. Everything counts — the "attack" frequencies at the onset of notes (which are tremendously different from instrument to instrument), the "decay" frequencies at the end of those notes, the various resonances set in motion by the materials used for instruments, the differences between media excited from outside (like the string or the drum) and those excited from inside, like the flute and the trumpet. And besides upper harmonics, there are also subharmonics. The world of music is incredibly rich and varied.

We could go further, but what our chart does is give you a beginning taste of what "Hz" (cycles per second) really mean musically. There are charts that show the harmonics of instruments as well as the fundamentals, but we've never seen one that shows the varying harmonic intensities of all instruments in comparison with each other. (If you have, please let us know!) As we said earlier, the point is music. While we at PSB are intent on doing justice to the sound of crashing buses and dinosaur footfalls as well as flutes and violins and snare drums, it's the sound of music that keeps our juices flowing.

[JBLnsince1959]

What I find interesting is that when I was young ( and many others), we could enjoy music almost no matter what speaker it came out of. Now don't get me wrong we all loved the JBL's because they were better and bought them. But as a teen and into the 20ies we could just enjoy the music and not worry

Now as we grow older it seems like we're trying to buy better cables, wires, amps, speakers, rework crossovers etc to get to the point where we were 30 years ago and just enjoy the music.

Sometimes I wonder how much of our love for the "older" JBL's is simply a search for our youth and how we heard then. Or how much "improving" the speakers is trying to makeup for our hearing loss.

[JBL 4645]

Mr. Widget

Good topic, perhaps it should be made into a sticky thread.

I’m 39 years old and I’m rather surprised I can hear a sine wave of up to 16.000KHz, I’ve leaned to lessen the sound level slightly over the years, has high frequency sounds can do irreversible damage top the tiny little hairs inside our ears!

All the literature that I have read over the years concerning this matter, I have absorbed, an 8 hours duration with a sound pressure level of 85db is deemed safe for human consumption, with irregular peaks up to 105db for short duration, films tend not to be overpowering, has there is a quite scenes and loud scenes, and demanding on the artist design of the soundtrack, some are quite pleasant, and the remaining few are Just Bloody Loud! And that’s when an audio limiter will save your hearing from being battered silly day in and day out.

Most of the time I use earplugs when going out down town, this is due to the high noise levels of traffic, buses peak around +90dba!

Oh one other thing, 16.000KHz has got a very short wavelength, of about, less than 1”.

Equal loudness contours and audiometry - Test your own hearing

http://www.phys.unsw.edu.au/~jw/hearing.html

[JBL 4645]

I just checked my hearing range with the following link that I have provided, and given, that I’m in a cyber café at the present time, the NC background level is quite high.

I could make out 16.000KHz at –12db! If I was at home, it might have been far less.

Equal loudness contours and audiometry - Test your own hearing

http://www.phys.unsw.edu.au/~jw/hearing.html

Hearing loss, or hearing impairment
http://www.kidshealth.org/kid/health...mpairment.html

Save Your Ears

http://www.athensmusician.net/archiv...01_hearing.php

William Shatner almost killed himself because of the incessant ringing in his ears called tinnitus

[Don Mascali]

I just turned 60 and after years of:

USMC artillery Communications service
Motorcycles with straight pipes
Being an avid pistol shooter
NASCAR Winston Cup pit work
HVAC service on huge chillers
Mobile and club DJ work

I find it amazing that I can hear at all.
I can hear the compression with MP3 and some other formats and I can hear a sinewave sweep to 10K, but I can tell when my 2405s crossed at 9K are not working. I am carefull to use hearing protection when required and use a meter to check my listening level. (90 to 95 DBC normal and 105 for very brief periods.)
I would hate to loose more as I get older. It sure would be a waste of alot of fine JBL gear.

[JBL 4645]

Don


Hello there

Tinnitus, now I have had this since I was young, never knew what it was, and it just comes and goes, yet I can still hear up to 16.000KHz, strange.

Activity / Decibels / Typical Physical Response
Rocket launching / 180 / Danger level Threshold of pain
Gunshot
Jet engine taking off / 140 / Danger level
Military jet
Air raid siren
Shotgun
Hydraulic press (3 m away) / 130 / Limited ability to hear amplified speech. Noise may cause pain. Can damage hearing after 3.75 minutes exposure per day
Car horn
Propeller aircraft
Air-raid siren / 120 / Can damage hearing after 7.5 minutes exposure per day
Sand-blasting
Squealing pigs
Inboard motorboatTypical night club
Un silenced motorcycle (7m away) / 110 / Maximum vocal effort. Can damage hearing after 30 minutes exposure per day
Amplified Rock Music / 110 -130 / Can damage hearing after 3.75 – 30 minutes exposure per day
Helicopter
Motorized/power mower / 105 / Can damage hearing after 1 hour exposure per day
Jet takeoff @ 500m
Train horn @ 30m
Diesel truck
Pneumatic drill/jackhammer / 100 / Can damage hearing after 2 hours exposure per day
Heavy truck @ 15m
Busy city street
passing motorcycle
Lawn mower
Loud shout
Screaming child / 90 / Very annoying. Can damage hearing after 8 hours exposure per day
Average factory
Electric shaver / 85 / Busy traffic intersection
Motorway construction site
Outboard motor
Alarm clock (with bell)
Freight train (15m away) / 80 / Annoying
Motorway traffic @ 15m
Roadside traffic
Train horn @ 500m
Vacuum cleaner
Mixer
electric sewing machine
Noisy restaurant
Conversation in a loud voice / 70 /
Telephone use difficult.
Washing machine/dishwasher / 65 /
Light car traffic @ 15m
City or commercial areas
Noisy office
Normal conversation
Clothes dryer
Background music / 60 / Intrusive.
Quiet office / 50 / Speech interference.
Refrigerator / 45 /
Quiet residential area
Kitchen/bathroom
Public library / 40 / Quiet .
Leaves rustling
Very soft music
Recording studio
Living/dining/bedroom / 30 / Very quiet.
Threshold of sound perception / 10 / Just audible.
Threshold of hearing / 0 / Not audible.

[Rolf]

I agree with you guys. I just turned 54, an on my Denon technical cd I can hear 16000Hz. Maybe 17000Hz on my left ear, if I put my it very close to the 2405.

Widget. I can not understand that you do not hear a difference between a standard speaker wire. I use a speaker wire the costs about US$ 1000 here in Norway, and the difference is that "it gets more quite", and the instruments "do not disturb each other", if you know what I mean. I have the same experience with signal wires, but they also gives even more details to the music.

[JBL 4645]

This is what I exactly use “exactly” even right at this very moment in time!

[JBL 4645]

I agree with you guys. I just turned 54, an on my Denon technical cd I can hear 16000Hz. Maybe 17000Hz on my left ear, if I put my it very close to the 2405.

Widget. I can not understand that you do not hear a difference between a standard speaker wire. I use a speaker wire the costs about US$ 1000 here in Norway, and the difference is that "it gets more quite", and the instruments "do not disturb each other", if you know what I mean. I have the same experience with signal wires, but they also gives even more details to the music.

Rolf

Don’t use loudspeakers to do the test use the sound evaluator that I provide in the above posts, only use headphones, loudspeakers for this kind of test is crucial to use headphones, moving your head slightly in the room, will change the pitch of the frequency due to it’s wavelength!

Use headphones!

Also different frequencies can mask other frequencies, making it almost impossible to hear!

[Rolf]

Rolf

Don’t use loudspeakers to do the test use the sound evaluator that I provide in the above posts, only use headphones, loudspeakers for this kind of test is crucial to use headphones, moving your head slightly in the room, will change the pitch of the frequency due to it’s wavelength!

Use headphones!

Also different frequencies can mask other frequencies, making it almost impossible to hear!

I have always used my speakers to find out how high I can hear. In the days of vinyl I used a Danish/German record "Hi-Fi Stereo Test", where the sine waves was on a direct cut record. I can remember at the age of about 22 I could hear 19000Hz from that record. After using it for a few times the frequencies on that record was removed from the record by the needle on the pickup. I bought a new one, and could hear it again.

For the last 15 years or so I have used the Denon test CD, and my hearing has gone down from 18000Hz to 16000Hz over that time.

I think this is a good indication of my hearing abilities. Or?

[Bob Womack]

Typically females hear more acutely than males do. (But for some reason don't seem to get the audio bug like we do.) (-Snip-)Widget

I was recently asked by a friend why more women aren't involved in my field, audio engineering. What I've noticed over twenty-five years in recording is that women simply aren't interested in the field. I also knew that part of my job, repeatedly listening to sounds while I adjust them, drove my wife nuts. As part of answering my friend, I visited the website of WAM, the "Women's Audio Mission", an organization that attempts to overcome the disparity in representation of women in professional audio. Throughout their pages, there is a Flash feature that quotes "Quick Facts" about women in audio, such as representation statistics. There on the site they confirmed that women have better high-end hearing than men but they also confirmed that women have a lower tolerance for repeated sounds. Perhaps we have our answer right there.

Back to the main topic of the thread, hearing is a complex thing. We don't just loose our hearing. You see, the mind has auto-leveling gear that protects us from overload by closing down the amplifier when sounds get too loud and increases sensititvity when we need to hear a quiet sound better. This same gear compensates when transduction of part of the spectrum is inhibited by hearing loss by raising the gain in that frequency region. As you have probably witnessed, when you turn up the gain on your audio systems, as the gain comes up, so does the "self noise", the artifact of electronic activity in any electronic sound reproduction system. In the stereo it shows up as hiss. In analog days, you set your listening level by jacking up the background noise on either a tape or disk 'till you could hear it and then backing it off to a memorized level. These days, with digital sources and lower noise floors, you'd deafen yourself with the first note with that practice.

Anyway, as your hearing declines/or or is damaged, your mind psychoacoustically jacks up the level in the damaged area to compensate. Your ear's "self noise" rises as well, and is recognized as a problem called "tinnitus" or ringing of the ears. When narrow-band sound is played in the presence of a broad-band sound of near intensity, the narrow-band sound is "masked" by the blanket of the broad-band sound, and the mind has a hard time distinguishing it. This effect causes it to be hard to extract a the foreground sound from the background as you age.

Meanwhile, you have some individuals who, despite presbycusis, seem to be able to discern material in ranges where they have limited hearing. I guess I'm not surprised. We don't typically loose all of our hearing in those ranges. We do become severely impared and the mind compensates, causing an increase in the self noise that further complicates hearing. However, some people, possibly due to training and practice before loss, appear to have the ability to "steer" their senses to somehow detect more than expected in those ranges.

I read an article recounting the experiences of amous console designer Rupert Nev concerning the hearing of then-middle-aged engineer Geoff Emerick in the ultrasonic range. Never was called to troubleshoot an analog console that just didn't sound right by the rather famous recording engineer. Neve put the scopes on the input modules of the console and found no differences in the audible range between known-good modules and the problem modules. He then swept up into the ranges above. He found no problems until he reached the 54khz range, where he discovered a little peak in the response. When he investigated the circuit, he discovered that the problem modules were a later "mark" of the same circuit. In the later "mark", one component, a filter cap in the transformered input affecting only the frequencies above 50k, had been omitted as superfluous because it didn't affect the audible range. Neve supplied caps and put the modules on the scopes again, observing that their response was then indentical to the other channels through 100k. He then conducted a blind listening test with his client engineer with known-good, "fixed", and identified "bad-sounding" moduless. His client was easily able to identifty the bad sounding modules, but the known-good and "fixed" modules were identified as identical. According to every criterion measurable by Neve, the only characteristic that had changed was the ripple at 54khz.

Does that mean Emerick could hear 54khz? I don't know. I doubt it. It does mean that he could hear the difference produced by an alteration that only affected the response in that frequency of the circuit. Think on.

Bob