Subject: Re: standards of speech intelligibilty for the hearing impaired? From: Christine Rankovic <rankovic@xxxxxxxx> Date: Thu, 21 Feb 2008 12:16:46 -0500 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>This is a multi-part message in MIME format. ------=_NextPart_000_000B_01C87483.A0EDB590 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Dear Dick, Chuping, and auditory.org list: =20 Thank you (Dick) for your summary of Brian Moore's talk. I wasn't = present, but I am familiar with Brian's ideas on this topic. =20 Contrary to Brian's assertion that the audiogram isn't enough, I have = had considerable success predicting speech intelligibility scores for = hearing-impaired listeners using just the audiogram. I use Harvey = Fletcher's full-blown Articulation Index [H. Fletcher and R.H. Galt = (1950), J. Acous. Soc. Am. 22, 89-151]. To use the AI, I model the = hearing loss as noise, and calculate expected masking spread for any = external noise, and then plug these into an otherwise unaltered Fletcher = calculation. =20 I have published three evaluations of prediction accuracy of Fletcher's = AI for hearing-impaired listeners. These included quiet and noisy = conditions (steady-state noise, not fluctuating), amplified and filtered = speech, and a variety of audiograms [C.M. Rankovic (1997), Chapter 26 in = Modeling Sensorineural Hearing Loss, edited by W. Jesteadt, Erlbaum, = Mahwah, NJ; C.M. Rankovic (1998), J. Acous. Soc. Am. 103, 1043-1057]. I = also evaluated Brian's dead region hypothesis, using Brian's own = published data, and I was able to predict his speech intelligibility = scores with very good accuracy [C.M. Rankovic (2002), J. Acous. Soc. Am. = 111, 2545-2548]. =20 I've recently extended Fletcher's AI calculation to predict binaural = speech intelligibility for normal and hearing-impaired listeners. This = is necessary because, after all, most hearing aid fittings are binaural. =20 I believe there are important implications of my success with Fletcher's = articulation index for hearing-impaired listeners: =20 1. Fletcher's calculation is the culmination of decades of basic = research at Bell Labs that investigated the normal processes of hearing = [Fletcher, H. (1995), edited by J.B. Allen, The ASA Edition of Speech = and Hearing in Communication available from http://asa.aip.org, C.M. = Rankovic and J.B. Allen (2000), Study of Speech and Hearing at Bell = Telephone Laboratories, CD available from http://asa.aip.org]. As such, = it includes extensive psychoacoustical modeling that considers intensity = level effects, loudness growth, masking spread, and more. Fletcher's = rigorous and elaborate efforts led to a robust model for normal = listeners to which extensions for hearing loss can be added.=20 2. There is no denying that there are many psychoacoustical = abnormalities associated with hearing loss--such as abnormal temporal = processing mentioned above. Researchers (including myself) have = struggled for decades to quantify the contribution of these factors to = speech intelligibility. Nevertheless, it seems that the AUDIOGRAM = encompasses these factors in a way that is sufficient for predicting = speech intelligibility. =20 =20 Within the next couple of months, I will make available a simple-to-use = version of my AI calculation. It will feature audiogram entry and = binaural capability. Please contact me if you are interested and I will = keep you posted. =20 Christine Rankovic, PhD rankovic@xxxxxxxx ------=_NextPart_000_000B_01C87483.A0EDB590 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 6.00.2900.2180" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>Dear Dick,=20 Chuping, and auditory.org list:<?xml:namespace prefix =3D o ns =3D=20 "urn:schemas-microsoft-com:office:office" = /><o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>Thank you=20 (Dick) for your summary of Brian Moore=92s talk. I wasn=92t present, but = I am=20 familiar with Brian=92s ideas on this = topic.<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>Contrary to=20 Brian=92s assertion that the audiogram isn=92t enough, I have had = considerable=20 success predicting speech intelligibility scores for hearing-impaired = listeners=20 using just the audiogram.<SPAN style=3D"mso-spacerun: yes"> = </SPAN>I use=20 Harvey Fletcher=92s full-blown Articulation Index [H. Fletcher and R.H. = Galt=20 (1950), J. Acous. Soc. Am. 22, 89-151].<SPAN style=3D"mso-spacerun: = yes"> =20 </SPAN>To use the AI, I model the hearing loss as noise, and calculate = expected=20 masking spread for any external noise, and then plug these into an = otherwise=20 unaltered Fletcher calculation.<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>I have=20 published three evaluations of prediction accuracy of Fletcher=92s AI = for=20 hearing-impaired listeners.<SPAN style=3D"mso-spacerun: yes"> = </SPAN>These=20 included quiet and noisy conditions (steady-state noise, not = fluctuating),=20 amplified and filtered speech, and a variety of audiograms [C.M. = Rankovic=20 (1997), Chapter 26 in Modeling Sensorineural Hearing Loss, edited by W.=20 Jesteadt, Erlbaum, Mahwah, NJ; C.M. Rankovic (1998), J. Acous. Soc. = Am.=20 103, 1043-1057].<SPAN style=3D"mso-spacerun: yes"> </SPAN>I also = evaluated=20 Brian=92s dead region hypothesis, using Brian=92s own published data, = and I was able=20 to predict his speech intelligibility scores with very good accuracy = [C.M.=20 Rankovic (2002), J. Acous. Soc. Am. 111,=20 2545-2548].<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>I=92ve=20 recently extended Fletcher=92s AI calculation to predict binaural speech = intelligibility for normal and hearing-impaired listeners. <SPAN=20 style=3D"mso-spacerun: yes"> </SPAN>This is necessary because, = after all,=20 most hearing aid fittings are binaural.<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>I believe=20 there are important implications of my success with Fletcher=92s = articulation=20 index for hearing-impaired listeners:<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>1.<SPAN=20 style=3D"mso-spacerun: yes"> </SPAN>Fletcher=92s calculation is = the=20 culmination of decades of basic research at Bell Labs that investigated = the=20 normal processes of hearing [Fletcher, H. (1995), edited by J.B. Allen, = The ASA=20 Edition of Speech and Hearing in Communication available from <A=20 href=3D"http://asa.aip.org">http://asa.aip.org</A>, C.M. Rankovic = and J.B.=20 Allen (2000), Study of Speech and Hearing at Bell Telephone = Laboratories, CD=20 available from <A href=3D"http://asa.aip.org"><FONT=20 face=3DArial>http://asa.aip.org</FONT></A><FONT face=3DArial>]. = </FONT>As=20 such, it includes extensive psychoacoustical modeling that considers = intensity=20 level effects, loudness growth, masking spread, and more.<SPAN=20 style=3D"mso-spacerun: yes"> </SPAN>Fletcher=92s rigorous and = elaborate=20 efforts led to a robust model for normal listeners to which extensions = for=20 hearing loss can be added.</FONT></SPAN><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>2.<SPAN=20 style=3D"mso-spacerun: yes"> </SPAN>There is no denying that there = are many=20 psychoacoustical abnormalities associated with hearing loss--such as = abnormal=20 temporal processing mentioned above.<SPAN style=3D"mso-spacerun: = yes"> =20 </SPAN>Researchers (including myself) have struggled for decades to = quantify the=20 contribution of these factors to speech intelligibility.<SPAN=20 style=3D"mso-spacerun: yes"> </SPAN>Nevertheless, it seems that = the=20 AUDIOGRAM encompasses these factors in a way that is sufficient for = predicting=20 speech intelligibility.<SPAN style=3D"mso-spacerun: yes"> =20 </SPAN><o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>Within the=20 next couple of months, I will make available a simple-to-use version of = my AI=20 calculation.<SPAN style=3D"mso-spacerun: yes"> </SPAN>It will = feature=20 audiogram entry and binaural capability.<SPAN style=3D"mso-spacerun: = yes"> =20 </SPAN>Please contact me if you are interested and I will keep you=20 posted.<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><o:p><FONT=20 face=3DArial> </FONT></o:p></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><FONT = face=3DArial>Christine=20 Rankovic, PhD<o:p></o:p></FONT></SPAN></P> <P=20 style=3D"MARGIN: 0in 0in 0pt; tab-stops: 45.8pt 91.6pt 137.4pt 183.2pt = 229.0pt 274.8pt 320.6pt 366.4pt 412.2pt 458.0pt 503.8pt 549.6pt 595.4pt = 641.2pt 687.0pt 732.8pt"><SPAN=20 style=3D"FONT-SIZE: 10pt; FONT-FAMILY: 'Courier New'"><A=20 href=3D"mailto:rankovic@xxxxxxxx"><FONT=20 face=3DArial>rankovic@xxxxxxxx</FONT></A><o:p></o:p></SPAN></P></= DIV></BODY></HTML> ------=_NextPart_000_000B_01C87483.A0EDB590--