Talk:Acoustic reflex

Miscellaneous Essential Informations
^That is a terrible title. Please change it to something else. It's not essential to me. — Preceding unsigned comment added by 193.1.104.12 (talk) 18:30, 15 September 2015 (UTC)

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I am doubtful of the validity of some of the content here. For example, the idea that we fail to hear someone if we speak over them because of our speech-induced reflex and not because of masking cannot be true, because the reflex only gives around 20dB of attenuation, and it takes a lot more than that to stop us hearing a conversation. It has to be masking by the louder source that is really preventing us from hearing. --Lindosland (talk) 17:48, 25 February 2008 (UTC)


 * You indicate that "it takes a lot more than that to stop us hearing a conversation" but that depends on the volume of conversation. There exists a base volume level between negative infinity and infinity such that -20dB would make it incomprehensible. 216.36.186.2 (talk) 18:04, 14 May 2008 (UTC)

While stating that the acoustic reflex does not protect against low frequency sounds, this article fails to mention the tensor tympani muscle which I understand tensions the outer eardrum and so reduces movement in response to low frequencies. --Lindosland (talk) 17:50, 25 February 2008 (UTC)

Vocalization-induced stapedius reflex
I think the three paragraphs starting with "Humming" should probably be removed. They are interesting but conjectural and I can't find any references to support them. In fact, literature suggests that the acoustic reflex is most active at frequencies less than 0.8 Hz. Mdscottis (talk) 22:58, 11 October 2012 (UTC)

I note also that there is significant research support summarized as follows: human psychoacoustic studies which suggest that contractions of the stapedius muscle significantly improve the detection of high-frequency tones masked by low-frequency noise and the identification of speech signals at high intensities (at high intensities, masking of the high-frequency components of speech by its low-frequency components becomes considerable. All in all, it makes me uncomfortable with the three paragraphs as previously stated  Mdscottis (talk) 22:14, 12 October 2012 (UTC)


 * I have removed the paragraphs regarding "humming". See talk section below. --JAC4 (talk) 12:38, 19 May 2013 (UTC)

More details
How quickly does this happen? How long does it last after the sound? Is the attenuation variable or on/off? Does the muscle get tired and loosen with prolonged sounds? Is the trigger threshold absolute or relative to background noise? How is the reflex tested? — Preceding unsigned comment added by Justanothervisitor (talk • contribs) 14:53, 2 November 2012 (UTC)

I really have no idea. For the attenuation of loud sound - ie 80 decibels and up, it is stated to be 40-80 msecs, so I think it really only protects against continuous loud noise. As regards the masking of low frequency background noise, I think it is continuous, always "on" unless something interferes with the stapedius reflex, and does not decay. 12th edition of Guyton and Hall textbook of physiology states "..To mask low frequency sounds in loud environments. This usually removes a major share of the background noise and allows a person to concentrate on sounds above 1000 cycles per second where most of the pertinent information in voice communication is transmitted," Mdscottis (talk) 16:38, 3 November 2012 (UTC)

As far as testing, during tympanometry in which compliance of the tympanic membrane is tested, a sound signal is injected, and the consequent temporary decrease in compliance, assumed to be due to the contraction of the stapedius on the stapes, is graphed. Mdscottis (talk) 03:28, 4 November 2012 (UTC)

Uncorrected content removed.
I tagged much of this article as citation-needed and/or original-research in July of 2012. It now May of 2013. As nobody has stepped up to claim validity in nearly a year, I am removing the dubious content, especially that related to the supposed intentional manipulation of the reflex (by e.g. humming) as a means to soften expected loud sounds. If you were the author of that content, it is now time to do your research before re-adding it. --JAC4 (talk) 12:20, 19 May 2013 (UTC)

tensor tympani contraction?
In the Characteristics and Effects section, the first bullet point says: "For most animals, the acoustic reflex is the contraction of both middle ear muscles: the stapedius and tensor tympani muscles. However in humans, the acoustic reflex only involves the contraction of the stapedius muscle, not the tensor tympani." But the second paragraph of the article says it *does* involve tensor tympani contraction, and describes the effect of its contraction. They both have citations, which I didn't follow because I wouldn't be qualified to judge whatever those link to anyway. Anybody know which is right? dan (talk) 06:42, 12 November 2019 (UTC)