Helmholtz and combination tones ("Richard M. Warren" )


Subject: Helmholtz and combination tones
From:    "Richard M. Warren"  <rmwarren@xxxxxxxx>
Date:    Fri, 5 Aug 2011 17:59:57 -0500
List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>

--Apple-Mail-9--729451927 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 As demonstrated by the thread on Helmholtz and combination tones, it is = pretty amazing that Helmholtz came up with equations describing the = production of combination tones although he apparently did not or could = not specify their structural and physiological bases. There is an = interesting indication of how this polymath=92s mind worked with limited = information that is indicated by a basic error he made in the first = edition of his Sensation of Tones (1863). He initially attributed the = frequency analysis occurring in the inner ear to tuned properties of the = rods of Corti that are adjacent to auditory nerve fibers on the basilar = membrane. He abandoned this theory in later editions when it was shown = that amphibia and birds lacked these structures. He then attributed the = frequency analysis to stretched and loaded nerve fibers on the basilar = membrane. However, his initial proposal concerning the rods of Corti is = eerily similar to the currently accepted role of bundles of stereocilia = as an initial stage in frequency analysis. Richard M. Warren=20 Research Professor=20 and Distinguished Professor Emeritus Department of Psychology University of Wisconsin-Milwaukee PO Box 413 Milwaukee, WI 53201 (414) 229-5328 --Apple-Mail-9--729451927 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 <html><head></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; = "><div><div style=3D"word-wrap: break-word; -webkit-nbsp-mode: space; = -webkit-line-break: after-white-space; "><div><div style=3D"word-wrap: = break-word; -webkit-nbsp-mode: space; -webkit-line-break: = after-white-space; "><div><p class=3D"MsoNormal"><span>As demonstrated = by the thread on Helmholtz and combination tones, it is pretty amazing = that Helmholtz came up with equations describing the production of = combination tones although he apparently did not or could not specify = their structural and physiological bases.<span>&nbsp;&nbsp;</span>There = is an interesting indication of how this polymath=92s mind worked with = limited information that is indicated by a basic error he made in the = first edition of his Sensation of Tones = (1863).<span>&nbsp;&nbsp;</span>He initially attributed the frequency = analysis occurring in the inner ear to tuned properties of the rods of = Corti that are adjacent to auditory nerve fibers on the basilar = membrane.<span>&nbsp;&nbsp;</span>He abandoned this theory in later = editions when it was shown that amphibia and birds lacked these = structures. &nbsp;He then attributed the frequency analysis to stretched = and loaded nerve fibers on the basilar = membrane.<span>&nbsp;&nbsp;</span>However, his initial proposal = concerning the rods of Corti is eerily similar to the currently accepted = role of bundles of stereocilia as an initial stage in frequency = analysis.<o:p></o:p></span></p></div><div><span><br></span></div></div><di= v><span class=3D"Apple-style-span" style=3D"border-collapse: separate; = font-family: Helvetica; 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; font-size: medium; "><span = class=3D"Apple-style-span" style=3D"border-collapse: separate; = font-family: Helvetica; font-size: 16px; 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; "><span class=3D"Apple-style-span" = style=3D"border-collapse: separate; 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>&nbsp;</div><div>Research = Professor&nbsp;</div><div>&nbsp;&nbsp;and Distinguished Professor = Emeritus</div><div>Department of Psychology</div><div>University of = Wisconsin-Milwaukee</div><div>PO Box 413</div><div>Milwaukee, WI = &nbsp;53201</div></div><div>(414) 229-5328</div><div><br = class=3D"webkit-block-placeholder"></div></div></span></span></span></div>= </div></div></div><br></body></html>= --Apple-Mail-9--729451927--


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