tag:blogger.com,1999:blog-3522311.post873374868220940921..comments2024-03-12T03:23:42.976-04:00Comments on NeuroDojo: “Can you hear me now?” The new record holder for hearingZen Faulkeshttp://www.blogger.com/profile/07811309183398223358noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-3522311.post-87127126268219968882013-05-16T20:32:14.011-04:002013-05-16T20:32:14.011-04:00Anyway , while reading about ultrasonics a while b...Anyway , while reading about ultrasonics a while back(possibly at http://berliner-ultrasonics.org/ ) that cleaning involving megasonics , which deals with higher frequencies , has more of a 'direction' to it than ultrasonic cleaning baths . With ultrasonic cleaning , you put the object in the cleaning bath , and it hits from all directions , but megasonic cleaning only works on the side of the object facing the megasonic wave source . Perhaps the hearing of the moths is affected similarly by the angle of the source / wave front of the higher pitched frequencies which appear to be in the megasonic range (If I remember correctly , megasonics are in the 100kHz to 500kHz range .). Alphahttps://www.blogger.com/profile/05037642776576653103noreply@blogger.comtag:blogger.com,1999:blog-3522311.post-26791771537369165552013-05-16T20:16:33.992-04:002013-05-16T20:16:33.992-04:00Hi , I found some supplemental information about u...Hi , I found some supplemental information about ultrasound and also wolf whistles . <br /><br />I thought some of you people reading this might possibly find these links interesting .<br /><br />S. Berliner, III<br />Consultant in Ultrasonic Processing<br />"changing materials with high-intensity sound" <br />http://berliner-ultrasonics.org/<br /><br /><br />Red Hot Riding Hood -<br />http://www.youtube.com/watch?v=YtcJ7gvJP0Q&list=PL41157B5CD0427B63Alphahttps://www.blogger.com/profile/05037642776576653103noreply@blogger.comtag:blogger.com,1999:blog-3522311.post-17406952986083907942013-05-11T09:13:21.372-04:002013-05-11T09:13:21.372-04:00Jayarava: Hm. I have always considered hair cells ...Jayarava: Hm. I have always considered hair cells to be sensory neurons. <br /><br />Dave: The last paragraph may be my mangled interpretation of the authors’ hypothesis. The “300 cycles” was a convenient random number. I just picked to try to illustrate what I thought the authors were hypothesising: the advantage of the high frequency is reaction time.<br /><br />As for traffic, it could well be. There probably is research on what kinds of sounds trigger moth behaviour. I’m not sure whether continuous ultrasound would do it.<br /><br />Thanks both for the excellent comments!Zen Faulkeshttps://www.blogger.com/profile/07811309183398223358noreply@blogger.comtag:blogger.com,1999:blog-3522311.post-14495640939683271992013-05-10T12:30:51.854-04:002013-05-10T12:30:51.854-04:00Thank you for the knowledge that moths can hear.
...Thank you for the knowledge that moths can hear. <br /><br />That last paragraph is a bit odd, though. Humans, unlike electronic pitch detection devices, need less than a period to detect the of a tonal sound. Also, the muscle reaction to impulse sounds is blazingly fast, due to the fact that the neurons between the hearing and the brain are short and efficient.<br /><br />I would assume a moth doesn't need 300 cycles to detect a sound. Also, listening in that long would not help, as most bats produce short bursts of sounds, around 40k to 60k or so. I doubt these will last 300 cycles. I would guess the moth is on the lookout for these bursts of sounds.<br /><br />The upshot of an ear that is sensitive to high frequencies might be that a small animal (with their ears close together) is still capable of doing some localisation of sounds. But with 4 neurons, I would guess the reaction is limited to "Blast, I hear something! Let's fly even more unpredictably than usual for now!"<br /><br />Since bats 'transmit' around 50kHz, I'm skeptic that there is any evolutionary pressure to evolve such really high frequency response. I do think that the size and the construction of the hearing can allow for such capabilities.<br /><br />I also have a question. Since traffic can produce high frequency content as well (it's loud and clear in my electronic bat detector), does traffic disturb flight patters of moths, other than due to drag?Dave Krooshofnoreply@blogger.comtag:blogger.com,1999:blog-3522311.post-58129315142107711532013-05-10T04:18:27.204-04:002013-05-10T04:18:27.204-04:00Hang on. In a human ear the ear drum only transmit...Hang on. In a human ear the ear drum only transmits vibrations mechanically to the cochlear. Hair cells in the cochlear turn vibrations into a signal, not neurons. Neurons "don’t convert anything into a signal". They interpret the signal from the cochlear. No doubt our ear-drum will vibrate well beyond 22KHz - it's the cochlear that determines the frequencies that we 'hear'. <br /><br />So what is the physiology of moth hearing and how many ear cell equivalents do the moths have to go with their four neurons? Jayaravahttps://www.blogger.com/profile/13783922534271559030noreply@blogger.com