Subject: Re: Infrasound and Infrapitch From: "Richard M. Warren" <rmwarren@xxxxxxxx> Date: Fri, 14 Aug 2009 12:17:28 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--Apple-Mail-24--767374635 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed; delsp=yes Content-Transfer-Encoding: quoted-printable The term infrasound can be misleading; while the frequency threshold =20= for hearing sinusoidal tones (at a reasonable amplitude) is roughly 20 =20= Hz, holistic frequency perception of complex waveforms (e.g., iterated =20= noise segments) continues for another five octaves of =93infrapitch=94 =20= below 20 Hz. Guttman and Julesz (1963) found that a percept they =20 called =93whooshing=94 occurred from roughly 0.5 to 4 Hz, =93motorboating=94= =20 from 4 Hz to 20 Hz. A noisy pitch is heard from 20 to 100 Hz, and a =20 pure noiseless pitch with interesting timbres from 100 Hz up to 16 or =20= 20 kHz. Thus, infrapitch and pitch form a seamless continuum of =20 perceptual =93iterance=94 extending for 15 octaves for stochastic =20 waveforms, subserved by partially overlapping neural mechanisms of =20 periodicity detection and place detection. Studies of infrapitch, since the pioneering study of Guttman and =20 Julesz, have been conducted by Irwin Pollack, Christian Kaernbach, and =20= myself. Infrapitch detection has also been studied in nonhuman =20 vertebrates. Richard M. Warren Research Professor and Distinguished Professor Emeritus Department of Psychology University of Wisconsin-Milwaukee PO Box 413 Milwaukee, WI 53201 --Apple-Mail-24--767374635 Content-Type: text/html; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable <html><body style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "><div><br></div>The term = infrasound can be misleading;<span> </span>while the = frequency threshold for hearing sinusoidal tones (at a reasonable = amplitude) is roughly 20 Hz, holistic frequency perception of complex = waveforms (e.g., iterated noise segments) continues for another five = octaves of =93infrapitch=94 below 20 Hz.<span> </span>Guttman = and Julesz (1963) found that a percept they called =93whooshing=94 = occurred from roughly 0.5 to 4 Hz, =93motorboating=94 from 4 Hz to 20 = Hz. A noisy pitch is heard from 20 to 100 Hz, and a pure noiseless = pitch with interesting timbres from 100 Hz up to 16 or 20 = kHz.<span> </span>Thus, infrapitch and pitch form a seamless = continuum of perceptual =93iterance=94 extending for 15 octaves for = stochastic waveforms, subserved by partially overlapping neural = mechanisms of periodicity detection and place = detection.<span> </span><div><br></div><div><span></span>= Studies of infrapitch, since the pioneering study of Guttman and Julesz, = have been conducted by Irwin Pollack, Christian Kaernbach, and = myself.<span> </span>Infrapitch detection has also been = studied in nonhuman vertebrates.<br = class=3D"Apple-interchange-newline"></div><div><br></div><div> <span = class=3D"Apple-style-span" style=3D"border-collapse: separate; color: = rgb(0, 0, 0); font-family: Helvetica; font-size: 16px; font-style: = normal; font-variant: normal; font-weight: normal; letter-spacing: = normal; line-height: normal; orphans: 2; text-align: auto; text-indent: = 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: = 0px; -webkit-border-horizontal-spacing: 0px; = -webkit-border-vertical-spacing: 0px; = -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: = auto; -webkit-text-stroke-width: 0; "><span class=3D"Apple-style-span" = style=3D"border-collapse: separate; color: rgb(0, 0, 0); font-family: = Helvetica; font-size: 13px; font-style: normal; font-variant: normal; = font-weight: normal; letter-spacing: normal; line-height: normal; = orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; = widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; = -webkit-border-vertical-spacing: 0px; = -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: = auto; -webkit-text-stroke-width: 0px; "><div style=3D"word-wrap: = break-word; -webkit-nbsp-mode: space; -webkit-line-break: = after-white-space; "><div><div><font class=3D"Apple-style-span" = size=3D"4"><span class=3D"Apple-style-span" style=3D"font-size: 14px; = "><b><br class=3D"Apple-interchange-newline">Richard M. = Warren</b></span></font> </div><div>Research = Professor </div><div> and Distinguished Professor = Emeritus</div><div>Department of Psychology</div><div>University of = Wisconsin-Milwaukee</div><div>PO Box 413</div><div>Milwaukee, WI = 53201</div></div><div><br = class=3D"webkit-block-placeholder"></div></div></span><br = class=3D"Apple-interchange-newline"></span><br = class=3D"Apple-interchange-newline"> </div><div><br></div></body></html>= --Apple-Mail-24--767374635--