Subject: Painfully loud sounds RE: AUDITORY Digest - 10 Nov 2004 to 11 From: Mortz <mmortz(at)WSU.EDU> Date: Fri, 12 Nov 2004 13:57:11 -0800 X-Virus-Scanned:by amavisd-milter (http://amavis.org/)Re: feeling of pain associated with cochlear hair cell loss. I have a bilateral sloping hearing loss. One ear has a severe to profound hearing loss and the other moderate to severe. Above 5000 Hz, there is almost no response in either ear. Both ears have significant "recruitment"; i.e., "abnormal loudness growth", but the left ear with the worst loss has a more dramatic problem. This type of hearing loss includes both outer and inner hair cells. In my case, it is a cumulative effect of childhood measles, mumps and adult Meniere's disease. Loudness Perception: A 80-85 dB sound to me is loud. This is common with people with more severe hearing losses. Many people with this kind of hearing loss perceive loudness growth as much or more than normal ears, once it is above their threshold. It makes fitting hearing aids more complicated, because the useful dynamic range is reduced. Compression hearing aids are beneficial. Pain Perception: If there is a sudden loud sound (>95 dB for me), the pain is very sharp and quite painful. It leads me to grab my ear to block the sound and try to get out of the environment very quickly. The pain is located in the ear region. My more damaged left ear feels pain more than the less damaged right ear. Speculation: The loss of outer hair cells destroys the feedback mechanisms that control adaptive cochlear filter bandwidth, loudness summation and other contributions to loudness perception. Pain might indicate abnormal upward spread of activation and abnormal loudness summation effects. The loss of automatic gain control from the outer hair cells may lead to over-stimulation of the remaining inner hair cells. Perhaps this might put stress on the tympanic membrane. The hair cells themselves may be weakened and not attach correctly to the membranes, making them more susceptible to pain. Theoretically, another potential factor might be excess endolymphatic fluid due to Meniere's disease. Often people with Meniere's disease (including myself), tend have significant recruitment and find louder sounds painful. However, I have doubts about the fluid pressure being the principal contributor to pain. My left ear had vestibular neurectomy surgery to reduce vertigo from Meniere's disease. As a consequence of this surgery, there is not supposed to be a buildup of endolymphatic fluid which could put pressure on the tympanic membrane. However, given that I still feel pain in the surgical ear, I don't think fluid pressure is the main reason. "Margaret Mortz, PhD " <mmortz(at)wsu.edu> ------------------------------ Date: Thu, 11 Nov 2004 18:38:16 -0500 From: "Didier Depireux, PhD" <ddepi001(at)UMARYLAND.EDU> -----Original Message----- From: AUDITORY Research in Auditory Perception [mailto:AUDITORY(at)LISTS.MCGILL.CA] On Behalf Of Automatic digest processor Sent: Thursday, November 11, 2004 9:00 PM To: Recipients of AUDITORY digests Subject: AUDITORY Digest - 10 Nov 2004 to 11 Nov 2004 (#2004-237) There are 3 messages totalling 85 lines in this issue. Topics of the day: 1. estimate of frequency response (2) 2. painfully loud sound ---------------------------------------------------------------------- Date: Thu, 11 Nov 2004 14:55:55 -0000 From: "Sean.O'Leary" <Sean.OLeary(at)UL.IE> Subject: estimate of frequency response Hi, I want to estimate the frequency response of a violin and guitar body, so that I can examine the excitation spectrum. The only method I have at my disposal is that of recording the body response to an impulse, i.e. tapping it. I would greatly appreciate any advice on optimising this estimate. Thanks, Sean. ------------------------------ Date: Thu, 11 Nov 2004 11:32:58 -0600 From: David Prince <dprince(at)ACOUSTICEXPERTISE.COM> Subject: Re: estimate of frequency response I'd recommend first reading up on Jurgen Meyer's Book, Acoustics and the Performance of Music or the papers that preceded. In doing room measurements with a violin as a source radiator (for realistic directivity response) I had most luck using a shaker on the bridge of the violin and using a sweep. At the time I was using TEF but any chirp and deconvolution method should work well. I had trouble using MLS as a stimulus. A brief writeup of my methods can be found in the prodeedings from the ASA Sabine centennial. Good Luck, David Prince >Hi, >I want to estimate the frequency response of a violin and guitar body, so >that I can examine the excitation spectrum. The only method I have at my >disposal is that of recording the body response to an impulse, >i.e. tapping >it. I would greatly appreciate any advice on optimising this estimate. > >Thanks, >Sean. ------------------------------ Date: Thu, 11 Nov 2004 18:38:16 -0500 From: "Didier Depireux, PhD" <ddepi001(at)UMARYLAND.EDU> Subject: Re: painfully loud sound On 11/9/04 7:56 PM, "jan schnupp" <jan.schnupp(at)PHYSIOL.OX.AC.UK> wrote: > nociceptive pathways and pain) I wondered: what determines whether we > would consider a particular sound to be painfully loud? I don't remember what it feels like to feel a "painfully loud" sound (whether it is felt inside the head, or just in the ear in general), but wouldn't the tympanic membrane itself be a good candidate for the pain sensation? The tympanum is innervated by four of the cranial nerves, providing general sensation through trigeminal, facial and vagal cranial nerves on the outside surface and glossopharyngeal nerve for the inside surface. I guess this might be partially answered if I knew whether people who lose their hair cells still perceive loud sounds as being painful right after hair cell loss, even though they might not perceive the sound as being that loud? Didier __ Didier A Depireux ddepi001(at)umaryland.edu didier(at)isr.umd.edu 20 Penn Str - S218E http://neurobiology.umaryland.edu/depireux.htm Anatomy and Neurobiology Phone: 410-706-1272 (lab) University of Maryland -1273 (off) Baltimore MD 21201 USA Fax: 1-410-706-2512 ------------------------------ End of AUDITORY Digest - 10 Nov 2004 to 11 Nov 2004 (#2004-237) ***************************************************************