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Medical Forum / Diseases and Disorders / Tinnitus / December 2003Tinnitus, real or imagined?
The last few nights I've noticed a faint ringing sound in my head when I go to bed. I'm trying to determine if I have tinnitus -- I play guitar in a band part-time -- or if there is some other explanation. My question is, what does someone with normal hearing "hear" in an otherwise quiet room? Is it normal to perceive a certain frequency of sound that isn't really there? My wife says she can hear a slight ringing as well, which is odd. Could electrical fields, AC adaptors or other sources explain this phenomenon? I last played with the band more than 6 weeks ago, and although my ears rang for a day or two afterward, I didn't notice the ringing again until a few nights ago. Is it normal for tinnitus symptoms to lag like that? I guess what I'm trying to determine is if I've scared myself into thinking I have tinnitus, when in fact my hearing is normal. As long as I am not thinking about it, I can go about my daily activities just fine. The only time I notice the ringing is in a very quiet room. I am seeing an audiologist next month. Any advice or knowledge in the meantime would be most welcome. Thanks. > The last few nights I've noticed a faint ringing sound in my head when I go to bed. I'm trying to determine if I have tinnitus -- I play guitar in a band part-time -- or if there is some other explanation. > My question is, what does someone with normal hearing "hear" in an otherwise quiet room? Is it normal to perceive a certain frequency of sound that isn't really there? > My wife says she can hear a slight ringing as well, which is odd. Could electrical fields, AC adaptors or other sources explain this phenomenon? > I last played with the band more than 6 weeks ago, and although my ears rang for a day or two afterward, I didn't notice the ringing again until a few nights ago. Is it normal for tinnitus symptoms to lag like that? > I guess what I'm trying to determine is if I've scared myself into thinking I have tinnitus, when in fact my hearing is normal. As long as I am not thinking about it, I can go about my daily activities just fine. The only time I notice the ringing is in a very quiet room. > I am seeing an audiologist next month. Any advice or knowledge in the meantime would be most welcome. Thanks. Hi James, The fact that one's ears can ring after exposure to a very loud noise (shotgun blast, loud concert) suggests that exposure to loud noise is one of the causes of tinnitus. Other events, like taking aspirin, can also temporarily induce tinnitus. Usually some time after the event (or dosage) the tinnitus goes away and this describes my personal experience up to a point in time a few years ago when the tinnitus became permanent. Maybe repeated "insults" to the auditory system eventually lead to the permanent condition, maybe not, but most hearing professional believe they do. If you don't protect your ears when playing in that band you may be at risk of developing more severe tinnitus and that isn't fun at all. Stick around, and let us know what your audiologist says. Bill >My question is, what does someone with normal hearing "hear" in an otherwise quiet room? ................ According to the Heller and Bergman study (1953) they hear a variety of sounds identical to tinnitus sounds. smn > >My question is, what does someone with normal hearing "hear" in an otherwise quiet room? > > ................ > > According to the Heller and Bergman study (1953) they hear a variety > of sounds identical to tinnitus sounds. Wich means that if you in a quite room are asked to listen for the sounds . . . most people will hear some thing like tinnitus. >> According to the Heller and Bergman study (1953) they hear a variety >> of sounds identical to tinnitus sounds. > >Wich means that if you in a quite room are asked to listen for the sounds . >. . most people will hear some thing like tinnitus. ...................... Not exactly, but very close. In the Heller and Bergman experiment, they were not asked to listen to their own sounds and describe them. They were asked to listen for a sound that they were told was being introduced to the soundproof room and descrribe *it* - but no sound was ever introduced to the room. So what they heard and described were their own sounds, but they didn't know it at the time. smn > In the Heller and Bergman experiment, they were not asked to listen to > their own sounds and describe them. They were asked to listen for a > sound that they were told was being introduced to the soundproof room > and descrribe *it* - but no sound was ever introduced to the room. So > what they heard and described were their own sounds, but they didn't > know it at the time. I used to have perfect hearing, and "aced" my hearing test (so to speak) a few years ago. That was before I got the mild(?) case of tinnitus I have now. Yeah, I know T isn't necessarily connected with hearing loss... Anyway... I would be put in a sound proof box, with a head phone on my head. I then would have to press the left or right button depending on whether I heard a sound in my left or right ear. If I remember correctly, there was always a slight sound "in my head", so it was really difficult to pick out the highest, faintest tones, although I did manage to do so of course. In any case, I didn't have tinnitus back then, but I still had "sounds" in my head, although it was more like hearing one's own blood flow rather than ringing. Perhaps. I know I didn't have tinnitus because I never even noticed the "natural" sounds in my ear the way I notice the T now. Hi James Happy Gibson and Fenders to you! I'm afraid that although the idea of wearing earplugs in the band is a sensible one, it isn't as simple as that. What you could be better advised to do, is to get a fitted pair of musician's earplugs which attenuate only 10 or 15 decibels. You see if you plug up your ears with full hearing defenders, you will risk hearing more tinnitus, as you are simulating "the quiet room" and the anechoic chamber and so "head noise" as we used to call, it will be evident. Also you can't hear your own playing dynamics to blend properly with the other instruments on stage. Notice how artistes today wear hearing aid mini speakers in their ears which are cordless and mixing the sound of their own voice properly in balance with the band so they can hear themselves sing above all that din. In any orchestra or band you have to control by how much you plug the sound up so you don't end up "shouting" with your instrument thinking you're only playing at normal level. This is why people who put headphones on and listen to music yell at you when they speak because they are stopped from hearing their own voice. The composer John Cage was told by a hearing specialist that when he heard two sounds in his ears after spending time in an anechoic chamber in silence, he was hearing 1. the sound of his blood stream and 2. the sound of his nervous system. I can't verify how true that was but it does make sense to me. I heard loud tinnitus when losing consciousness as an anaesthetic was given me when I was 7 in 1953. I heard it again when I was 9 having laughing gas at the dentist. I think it's always there in the system but of course noise-damage can make you hear it permanently not just in a silent room. So watch out. Take precautions, take care. Db7 b9 b13 to you. Laurie > Hi James > Happy Gibson and Fenders to you! [quoted text clipped - 8 lines] > Also you can't hear your own playing dynamics to blend properly with > the other instruments on stage. The attenuation values on musician's hearing protectors should not be taken as real world values. Those were determined under the best of circumstances in a lab situation. In the real world, I would expect that you would get less protection than the nominal values. What is true is that the 25 dB insert attenuates more than the 15 dB which attentuates more than the 9 dB. > Notice how artistes today wear hearing aid mini speakers in their ears > which are cordless and mixing the sound of their own voice properly in [quoted text clipped - 6 lines] > headphones on and listen to music yell at you when they speak because > they are stopped from hearing their own voice. That's not really how it works, Laurie. They shout because they're being fed relatively loud sound into their ears. So they are shouting to be able to hear themselves because of the masking effect of that sound. It's called the cocktail party effect. We hear the sound of our own voice predominantly through the bone conduction channel and not via air conduction from our mouths to our ears. So if you just plug up your ears, your own voice will echo and sound louder to you because you're getting a greater proportion of low frequency input to your inner ears because of the greater efficiency of the bone conduction channel. This is called the occlusion effect. > The composer John Cage was told by a hearing specialist that when he > heard two sounds in his ears after spending time in an anechoic > chamber in silence, he was hearing 1. the sound of his blood stream > and 2. the sound of his nervous system. The former might have been true if the somatosound was pulsatile. I don't know about the sound of his own nervous system. That just seems to me to be another way of saying tinnitus. HNG > That's not really how it works, Laurie. They shout because they're being fed > relatively loud sound into their ears. So they are shouting to be able to > hear themselves because of the masking effect of that sound. It's called the > cocktail party effect. This isn't the cocktail party effect. It's the Lombard phenomenon. We raise the level of our own voices so that we can hear ourselves above the background noise. HNG >> you're only playing at normal level. This is why people who put >> headphones on and listen to music yell at you when they speak because >> they are stopped from hearing their own voice. > >That's not really how it works, Laurie. They shout because they're being fed >relatively loud sound into their ears. So they are shouting to be able to Yes it is, that's exactly what I was saying. People putting headphones on, you and me and listening to music through them, shout when they speak because they are trying to "normalize" the volume of their own speech being fed back into their ears and of course the sound of their own voice doesn't get fed back to their own ears so they shout louder to try and hear their own voice. Take away the normal input acoustically from your ears and you shout. Put earplugs in your ears when you're playing an instrument and you can't hear it playing softly so you play it louder and you think it's still soft. That is the only criticism that all musicians have made to me about the use of earplugs. Regardless of how well or not well they attentuate they are at least an assistance in removing some of the overdose-damage that orchestral players are getting when working full-time in such orchestras. Any attenuation is a good thing. >through the bone conduction channel and not via air conduction from our >mouths to our ears. So if you just plug up your ears, your own voice will We're talking at cross purposes here. The person shouting with headphones on is doing so because of music playing in the ears and drowing their own voice. The person who is acoustically deaf, shouts more when talking to people. I know, because I do so myself. When my hearing aids are switched off I get far less feedback telling me how loud my voice is, and I shout without knowing I am. The moment I switch the hearing aids on, I am fed the normalized sound of my own voice and I speak at normal levels. I have proved that by my wife saying you're shouting. I say "Am I, sorry, I haven't put my hearing aids in yet". Noise drowns noise especially if one is louder than the other. Musicians on stage who strut about singing have to be fed "the mix " otherwise they can't hear themselves sing. By far the majority of the sound we hear of our own voice is from the input to the ear acoustically. Bone conduction is a lesser volume input. So I'm sorry but I dispute your comments about it being majority through bone conduction. It isn't. It's like Flanking Transmission through joists ceilings and floors compared to the direct transmission of sound through a wall. One is always greater than the other. And I think you're wrong about the bone conduction. When people who are totally deaf are given transducers to provide sound through bone conduction it's a very inferior level of sound and detail compared to real acoustic input to the normal ear. Laurie > By far the majority of the sound we hear of our own voice is from >the input to the ear acoustically. Bone conduction is a lesser >volume input. .............. As a person who wears hearing aids, my own experience mirrors Laurie's exactly. Howard, are there any studies indicating that bone conduction is a greater factor than air conduction in hearing your own voice - because I have a really hard time believing it. smn > > By far the majority of the sound we hear of our own voice is from > >the input to the ear acoustically. Bone conduction is a lesser [quoted text clipped - 8 lines] > > smn Hmmm. I tried this experiment: In the quiet of my home I repeated the word "yes" while plugging my ears. I perceived nearly the same loudness with or without having them plugged. I repeated this test using the word "No" and the perceived loudness increased when I plugged my ears! I tried this over and over with the same result each time. Then I turned the radio on and plugged my ears while listening to it. The perceived loudness dropped about 75%. I'm not surprised that the efficiency of bone conduction would vary across a spectrum of frequencies but I was surprised by how significant it's contribution was to my overall hearing ability. Once I came to grips with how efficiently my bones conducted sound from my vocal cords to my cochlea I began wondering why the word "no" would be perceived louder with my ears plugged. I concluded that this sound was more efficiently reflected from my home's walls and that a percentage of it arrived back at my cochlea out of phase with the sound coming from my vocal cords. The two out-of-phase sounds at the same frequency would both cancel and distort... a process known in my industry as multi-path distortion. >Hmmm. I tried this experiment: In the quiet of my home I repeated the word >"yes" while plugging my ears. I perceived nearly the same loudness with or >without having them plugged. I repeated this test using the word "No" and >the perceived loudness increased when I plugged my ears! I tried this over >and over with the same result each time. ............... I think something else is going on ... If you plug your ears, your voice should sound softer even if the predominant factor in the loudness of your own voice is, indeed, bone conduction, shoudn't it? I mean in covering your ears you are removing the air conduction component - not increasing the bone conduction component. Confusing to me - smn > >Hmmm. I tried this experiment: In the quiet of my home I repeated the word > >"yes" while plugging my ears. I perceived nearly the same loudness with or [quoted text clipped - 15 lines] > > smn The results would vary with the dimensions of the room and where one is within that confine. I doubt if I'm the only one who frequents this group that has been seated at a "dead spot" in an auditorium, for example, where sounds reflected from different surfaces cancel. In the experiment, the air conduction component would add to or subtract from the bone conduction component depending upon the round trip distance from the mouth to a reflective surface to the point at which the two waveforms combine. >The results would vary with the dimensions of the room and where one is >within that confine. I doubt if I'm the only one who frequents this group [quoted text clipped - 3 lines] >component depending upon the round trip distance from the mouth to a >reflective surface to the point at which the two waveforms combine. I wonder why you're not considering the the two crucial components that are modifying the formation of the sound when you say yes or you say no, and that is the oral cavity shape and the way an "O" vowel causes a totally different jaw position and use of the vocal chords to using the word "Yes" Also you have a consonant on the end of "ye s" and I think I'm right in saying that the high frequencies don't conduct down the bones of the jaw and into the eardrum with the same efficiency as low frequencies. This is why you have a sub-whoofer bass speaker in Home Cinema surround sound and it's position is wholly unimportant because the ear is far more confused about pinpointing directionality of bass notes than it is the treble or high-frequencies. I know that for me I can't hear anywhere near as much consonant and sibilant detail in the bone conducted sound as I do from the direct acoustic in the ear canal sound. So with the treble effectively turned off, the bone conducted sound to me sounds quieter than the sound directly in the ear. To my perception if I plug my ears up the effect is the same as being more deaf. I lose all the treble and the sound seems like I'm listening under water to the sound above the water. This phenomenon is a lot less simple than mere apparent volume or amplitude. -- Laurie > >The results would vary with the dimensions of the room and where one is > >within that confine. I doubt if I'm the only one who frequents this group [quoted text clipped - 32 lines] > -- > Laurie Hi Laurie, My simple test was a reaction to the question Stephen posed to Howard: "Howard, are there any studies indicating that bone conduction is a greater factor than air conduction in hearing your own voice - because I have a really hard time believing it." Stephen's question is limited to hearing one's own voice. It is easy to minimize the air conduction component by simply plugging one's ears but the bone conduction component is constant. Here is another interesting experiment that demonstrates the effect of multi-path distortion: Whistle something repetitive and walk from room-to-room. The perceived loudness and tonal quality will vary remarkably. In this experiment everything is constant but the nature of the confinement which, in turn, modifies the sound through the addition and subtraction of reflected sound pressure waves. Repeat the test but this time with your ears plugged. The perceived loudness and tonal quality will be constant as you move from room-to-room. Conclusion: Air conduction is the bigger factor in the perceived loudness and tonal quality of one's own voice because multi-path distortion modifies that perception. Unfortunately, the test says nothing about interpretation because, of course, we know what we are saying or whistling. Well, some of us think we do. :-) Bill >Here is another interesting experiment that demonstrates the effect of >multi-path distortion: Whistle something repetitive and walk from >room-to-room. The perceived loudness and tonal quality will vary "Eigentones" are responsible for this effect. A room with equal dimensions ie a cube, will have many resonant frequencies and will boom more, which makes them the worst shape for hi-fi music listening through speakers. It's also called "The singing in the bath effect" The unfurnished hard walled bathroom and the acoustically resonant cavity of the bath tub make resonances that make you sound like Pavarotti when you sing just normally in the bath ! But there's another factor here which is modifying this effect when plugging the ears. I noticed when I had my first pair of digital hearing aids fitted with ITE molds made which feed the two BTE devices, that my right ear when the plastic mold was inserted caused me to hear my own voice heavily over-resonated as a result of the "earplug" which is the mold touching the sidewalls of the ear canal and finding a kind of acoustic G-spot if you'll pardon the expression! I found it so badly over-amplified the bass component of my own voice that I had to ask the audiologist to shave a load of plastic off it so that it didn't reach so far into the ear canal. This cured the problem but he had to shave about a quarter inch off its length and that of course put the outlet of the hearing aid pipe a bit further away from my ear drum compared with the left ear canal which didn't give this problem. I guess I'm saying here that placing ear plugs in contact with the walls of the ear canal can seriously affect one way or another the level of vibration conduction down the canal and this will depend on the factor brought about by the compliance of the canal and how much you "stop-up" that compliance with varying amounts of elasticity with the ear plugs. It is already widely known that wearing ear plugs while riding a motorcycle will only attenuate the high frequencies. The ears still pick up the low frequency roar of the engine and the wind amplified by the crash helmet. Cheers Laurie "Bob" <nobody@somewhere.now> wrote in part: >Hmmm. I tried this experiment: In the quiet of my home I repeated the word >"yes" while plugging my ears. I perceived nearly the same loudness with or >without having them plugged. I repeated this test using the word "No" and >the perceived loudness increased when I plugged my ears! I tried this over >and over with the same result each time. One normally controls their speaking loudness by the sound of one's voice. I'm not sure you can control the loudness while simultaneously testing the effect of earplugs on it!  SignatureJim Chinnis / Warrenton, Virginia, USA Want to discuss Meniere's? See http://groups.yahoo.com/group/MenieresDG > "Bob" <nobody@somewhere.now> wrote in part: > [quoted text clipped - 7 lines] > not sure you can control the loudness while simultaneously testing the effect > of earplugs on it! You are right, Jim, but it is fairly easy to say "yes" or "no" with the same amplitude if the words are said in rapid succession while one's ears are plugged and unplugged with the tips of their fingers. This would be much more difficult using ear plugs/muffs. Try the test doing it that way. "Bob" <nobody@somewhere.now> wrote in part: >> "Bob" <nobody@somewhere.now> wrote in part: >> [quoted text clipped - 18 lines] >plugged and unplugged with the tips of their fingers. This would be much >more difficult using ear plugs/muffs. Try the test doing it that way. "Yes" falls in loudness. "No" stays the same or rises slightly. Seems pretty consistent with the bone conduction route being the main one at work here and with the frequency-dependent nature of bone conduction pathways. The rise in loudness for "no" is the occlusion effect. Bone conduction involves several different pathways. One is the actual vibration of the air column in the external ear canal (caused by bone vibration) that then propagates like air-conducted sound to the inner ear. When the ear canal is blocked ("occluded"), this vibration is stronger and there is a more sound energy propagated to the inner ear. SignatureJim Chinnis / Warrenton, Virginia, USA Want to discuss Meniere's? See http://groups.yahoo.com/group/MenieresDG <snip> > >You are right, Jim, but it is fairly easy to say "yes" or "no" with the same > >amplitude if the words are said in rapid succession while one's ears are [quoted text clipped - 11 lines] > blocked ("occluded"), this vibration is stronger and there is a more sound > energy propagated to the inner ear. Wow, you and I had the same result! I like what Laurie had to say about why "no" would be louder than "yes" with the ears plugged because my experience tells me that different mediums (concrete/wood/bone/skin) all act as "band pass filters" the efficiency of which varies considerably with signal frequency. When the ear canal is >blocked ("occluded"), this vibration is stronger and there is a more sound >energy propagated to the inner ear. As said in the reply to Bob today, this is all dependent upon the type and elasticity of the ear plug. It has a very strong modifying factor according to how firmly it's pushed in the ear and what the plug is made of. Mateials not only modify the response of the ear canal wall, but add or subtract acoustic transparency according to the density of the material used, Foam/ Rubber/ Wool/ Acetate etc etc. Laurie > When the ear canal is > >blocked ("occluded"), this vibration is stronger and there is a more sound [quoted text clipped - 10 lines] > > Laurie About how sound waves combine and how efficiently they propagate bone, skin, air etc.: http://www.physics.lsa.umich.edu/chupp/Physics290/2003Lecture19.pdf sssssssssss is a high fq sound.....as in yes.......hard to conduct via bone. oooooooooooo is a low fq sound......as in no........easy to send through solid substances, like bone! Earplugs can block out, at best, about 30 dB of air conducted sound. They cannot block bone conducted sound at all........and most bone conducted sound is lower in frequency (longer waves) and passes through our whole body............pleasantly in the case of drums and music, awful in industrial applications......... MJ >Earplugs can block out, at best, about 30 dB of air conducted sound. And I wanted to add that this is the max even with earmuffs on top or your head wrapped in towels. There are 3 ways sounds enter the inner ear: 1) via the ear canal (air) 2) via the bone of the skull which shake the inner ear fluids (bone) 3) via the vibrations in the world that shake the bones that then shake the tiny bones of the middle ear space, which then sends waves into the inner ear via inertia (bone-air) That's it! Low fqs are notorious bone shakers........highs are easier to block via earplugs.......... MJ > >Earplugs can block out, at best, about 30 dB of air conducted sound. > [quoted text clipped - 15 lines] > > MJ Right, Marsha, and this also explains why one can listen to a tape recording of two voices, your own and someone else's, and discover that their voice sounds normal but your own voice sounds a little strange. In that case, the bone conduction component of your own voice is minimized. Your SOOOOOOO Smart Bob... Ya shoulda been an oddiologist :) - jean >Right, Marsha, and this also explains why one can listen to a tape recording >of two voices, your own and someone else's, and discover that their voice >sounds normal but your own voice sounds a little strange. In that case, the >bone conduction component of your own voice is minimized. > Your SOOOOOOO Smart Bob... > > Ya shoulda been an oddiologist :) > > - jean Lean Jean, the tinnitus queen. She perks up her lobes, dons her tin cap Gives you a wink and never looks back. :-) >Gives you a wink and never looks back. > >:-) ............ Didn't I spot you at Billys Bar Saturday night? - jean exotic dance team >That's it! Low fqs are notorious bone shakers........highs are easier to >block via earplugs.......... > >MJ Which explains that I was correct in my statement earlier in the thread where I said "It is already widely known that wearing ear plugs while riding a motorcycle will only attenuate the high frequencies. The ears still pick up the low frequency roar of the engine and the wind amplified by the crash helmet." Thanks for the explanation. Laurie >"It is already widely known that wearing ear plugs while riding a >motorcycle will only attenuate the high frequencies And what is weird about it is that no matter how fast u drive, i.e., 60 mph, the noise of te motorcycle will still damage your hearing...........it moves faster......... I had a professor in college who would make us prove that. MJ >And what is weird about it is that no matter how fast u drive, i.e., 60 mph, >the noise of te motorcycle will still damage your hearing...........it moves >faster......... Yes but that's not the end of the story. Research in the UK has shown that by far the majority of the damage to the hearing is done by the roar of the wind, amplified by the shape, nature and poor aerodynamics of all crash helmets. It's by far the greater noise than that coming from the motorcycle's engine. Engines vary in the character and loudness component that comes from their operation. The most engine-noise comes from the mis-named "Silencer" (mis-named in the UK - I know you call it a muffler in the USA) Silencer's don't silence and mufflers don't properly muffle, they just reduce a varying amount of loudness. But when you're riding on a Harley Davidson (known for being the noisiest motorcycles in the world, and which have mufflers that don't muffle and produce a din equivalent to an un-muffled propeller driven aircraft) the rider is in front of the source of the sound. The pillion gets some of it, but by far the major part of the noise is suffered by people standing nearby (passive damage)as the Harley rides past. When riding most motorcycles you can hardly hear the engine over the roar of the wind once you get above 60mph. Manufacturers of crash helmets won't address the issue of sound-deadening., They think their responsibilities end with making them protect your skull if you should hit the deck. Riding on a motorcycle with a normal crash helmet the noise has been measured in a wind tunnel and corresponds to these approximate figures in Decibels Dr Andrew McCombe and Dr Jonathan Binnington did some research testing various motorcyclists including Grand Prix riders and also some different makes of crash-helmet and came up with the following figures. 97db at 50mph Safe exposure no more than 30 minutes a day 107 db at 80mph Safe exposure no more than 3 minutes a day 118db was measured Wind-noise at 80mph 90db was measured at between 75 and 80mph Ear plugs help to reduce damage when riding. Rationing yourself to less riding per day even with earplugs helps even more. We have a speed limit in the UK of 70mph but you can ride up to 140mph on the Autobahn in Germany quite legally. Police riders in the UK probably suffer more than Grand Prix riders because they are doing more hours in the saddle and sometimes at high speed. I was doing well over 100mph when the opportunity presented itself. And in my work I was travelling 25,000 miles per year on a BMW. Regardless of the quiet engine and aerodynamic fairing, the wind-noise was still horrendous. Further damage to my outter-hair-cells of the cochlea was accumulated from the Piano Tuning, where peaks of 115db were being forced into my ears thousands of times per day ! So it's probably no wonder that I got tinnitus and Sensorineural Hearing Loss. I wish I'd been a Librarian ! -- Laurie >So it's probably no wonder that I >got tinnitus and Sensorineural Hearing Loss. I wish I'd been a >Librarian ! >-- I had no idea! What an interesting letter....I am going to print it out and send it to that old professor! MJ Stephen Nagler <nagler@tinn.com> wrote in part: >> By far the majority of the sound we hear of our own voice is from >>the input to the ear acoustically. Bone conduction is a lesser [quoted text clipped - 8 lines] > >smn If you have hearing loss (sensorineural loss) and wear hearing aids, the hearing aids boost the air-conduction pathway, making it dominant even for sounds that would--in a normal-hearing person--primarily be heard via bone conduction. I hear my own voice almost normally with my ears plugged. I just tried a combo of 30dB plugs and 28dB muffs with the same result. SignatureJim Chinnis / Warrenton, Virginia, USA Want to discuss Meniere's? See http://groups.yahoo.com/group/MenieresDG >If you have hearing loss (sensorineural loss) and wear hearing aids, the >hearing aids boost the air-conduction pathway, making it dominant even for >sounds that would--in a normal-hearing person--primarily be heard via bone >conduction. Ah this explains why my Audiologist who has no hearing defects outside that normally expected in a person in their 40's can test a hearing aid and knew ( as soon as he tried the make and model that he sold me) that the hearing aids were excellent in their realism. His criteria was that when he put them in and switched them on, he found that what he heard around him sounded so normal that he questioned whether they were switched on or not. This made him think that if they produce a sound that doesn't have a hint of artificiality to him, then they must be really good transducers. All that was then needed for me was to "tweak" them to boost my strange areas of hearing loss in the "dips" parts of my spectrum and he put my hearing back to as near to normality as it's possible to get for someone who can't hear anything under 30db. But where you say the hearing aids "boost the air-conduction pathway" I think that is not quite right in my case because they don't add to the pathway from external natural sounds, they "replace it" with amplified digital representation of the external sound and boost it down the canal so I can hear a near perfect simulation of the sound shape and airborne-amplitude of the sound. Otherwise the molds act as ear plugs if I switch off the hearing aids. There is a tiny air vent in each one but the molds definitely attenuate or even block the natural air-column of sound coming in from outside. They produce an air disturbance of their own from the output speakers inside at the front end of the tube. Laurie A useful analogy is like the TV carrer wave. You turn on the TV. There is a hum and no station. Now the station comes on and no hum. The wind blows down teh antenae and the station is gone and the hum comes back. Its a carrier wave that is these to be modified by the electronic impulse from the sound conversion. This is what you hear in the anechoic chamber to a large extent. Murray Grossan, M.D. http://www.ent-consult.com http://www.hydromedonline.com http://www.tinnnitusrelief.net http://www.hydromedonline.com/presentingthehydropulse/ Maybe playing loud music in the band may cause the ringing in the ears... I have constant ringing, humming sounds all the time due to my Meniere's Disease... I hope that this is not what you have... Noises in the ears are not imagined..It is real.... |
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