Subject: Re: Impacts from ultrasound and infrasound From: =?ISO-8859-1?Q?Henrik_M=F8ller?= <hm@xxxxxxxx> Date: Wed, 12 Aug 2009 22:04:24 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Hi Amy Please let me mention the common misunderstanding that the human hearing "stops" st around 16-20 Hz. We do denote sound below 20 Hz as "infrasound", but it is not inaudible. Below these frequencies, the perception changes, and the tonal sensation disappears. But tones at least down to a couple of hertz can indeed be perceived by everyone. The lower the frequency, the higher the threshold. The sensation goes through the ear, not the body as often claimed. I think it is still unclear, if the sensation is from the cochlear or elsewhere in the ear. For a fairly recent review, please allow me to promote our article: Henrik Møller, Christian Sejer Pedersen: "Hearing at low and infrasonic frequencies", Noise & Health, Vol. 6(23), pp. 37-57 (2004). The idea of infrasound being inaudible has caused a number of misunderstandings, in particular in the popular press (but also in the academic literature). Best regards, Henrik Henrik Møller Professor Section of Acoustics, Department of Electronic Systems Aalborg University Fredrik Bajers Vej 7 B5 DK-9220 Aalborg Ø, Denmark Phone: +45 9940 8711 (direct) Phone: +45 9940 8710 (section office) Phone: +45 9940 9940 (switchboard) Fax: +45 9815 2144 (section office) mailto:hm@xxxxxxxx (personal) mailto:acoustics@xxxxxxxx (section office) http://acoustics.aau.dk Amy R. Scholik-Schlomer skrev: > Hi, > > I am emailing to ask the group if anyone can direct me to publications > (preferably reviews) on the impacts of ultrasound or infrasound on > humans/animals. Typically, impacts are only considered for those > noises that fall into a species auditory range, but I wanted to know > more about potential impacts/likelihood for impacts for those sounds > outside the auditory range (assuming they would be more physiological, > rather than behavioral, where an animal would have to hear the sound > in order to respond). > > I am coming at this from a bit different angle, since I am considering > this in the context of non-human hearing ranges (thus, infra- and > ultrasonic ranges may be different depending on the species), > specifically for marine species (fish, marine mammals, and sea turtles). > > In order not to clog up everyone's email boxes, you can respond to me > directly, if you like (email in my signature below). > > Thanks for your help, > Amy > -- > ____________________________________ > > Amy R. Scholik-Schlomer, Ph.D. > Fishery Biologist > NOAA's National Marine Fisheries Service > Office of Protected Resources > Marine Mammal & Sea Turtle Conservation Division > 1315 East-West Highway > SSMC III, Room 13605 > Silver Spring, MD 20910 > > Email: Amy.Scholik@xxxxxxxx > Phone: (301) 713-2322 x167 > Fax: (301) 713-4060 > http://www.nmfs.noaa.gov/pr/acoustics/ > ______________________________________