Subject: Re: [AUDITORY] A question about calibration of very high frequencies From: Etienne Gaudrain <egaudrain.cam@xxxxxxxx> Date: Fri, 31 May 2019 10:01:23 +0200 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--00000000000075d8af058a2a6c31 Content-Type: multipart/alternative; boundary="00000000000075d8ac058a2a6c30" --00000000000075d8ac058a2a6c30 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Sylvie, I also wondered what you meant by "exceptionally high"? Is that that in previous measures you didn't have this noise? Or is it that it is high in absolute terms (what are the numbers then)? High frequency noise can come from fans, neon lights, screens... Although the latter two tend to have narrow spectra. Faulty preamp on our sound level meter has also displayed HF noise in the past. -Etienne On Fri, 31 May 2019, 06:09 Bernstein,Leslie, <lbernstein@xxxxxxxx> wrote: > Hello-- > > In order to help, much more information is required: > > Exactly what equipment is it that you wish to calibrate? > What equipment are you using or do you have available to make the measure= s > of the desired signal and the associated noise floor? > > There are quite a few explanations for what you have found that can be > narrowed down based on the answers to the questions above. Given > reasonable assumptions of linearity and availability of precision > attenuators, it is often not necessary at all to make such measures at lo= w > levels. Whether that's true in your case will depend upon the details. > > Les > > > On 5/30/2019 12:18 AM, H=C3=A9bert Sylvie wrote: > > Dear List, > > > We would like to calibrate our equipment to verify that it is capable to > sending low-intensity narrowband noises just above auditory threshold. We > have found that the baseline noise levels were exceptionally high for ban= d > frequencies above 8kHz. Can anyone explain why this may be the case? Does > anyone have any suggestions for how to approach measuring very > low-intensity sounds? > > > > Thanks, > > *Sylvie H=C3=A9bert, **Ph.D., Professor* > > *School of Speech pathology and audiology* > > *Pavillon 7077, Parc ave. - 3rd floor - room 3001-34* > > *Faculty of medicine * | *Universit=C3=A9 de Montr=C3=A9al* > > [image: Universit=C3=A9 de Montr=C3=A9al] > <https://urldefense.proofpoint.com/v2/url?u=3Dhttp-3A__www.umontreal.ca_&= d=3DDwMFAw&c=3DEZxp_D7cDnouwj5YEFHgXuSKoUq2zVQZ_7Fw9yfotck&r=3D2Pw2GwelGcMR= 4953G-STHGpPJm2-pYYYSPmTwJk3sWM&m=3DOkvFOa7K4fB1QBWJHQgEB73pmn6Idw1HPEAnKHo= rrwk&s=3DSzYSjQbUnlR95fFm1YA1M5QOfS2ztq9rwWYdOMngcBQ&e=3D> > > > *Address : c.p. 6128, succ. Centre-ville, Montr=C3=A9al, * > > *H3C 3J7 **Tel: (514) 343-6111 #2594* > > *www.eoa.umontreal.ca > <https://urldefense.proofpoint.com/v2/url?u=3Dhttp-3A__www.eoa.umontreal.= ca_&d=3DDwMFAw&c=3DEZxp_D7cDnouwj5YEFHgXuSKoUq2zVQZ_7Fw9yfotck&r=3D2Pw2Gwel= GcMR4953G-STHGpPJm2-pYYYSPmTwJk3sWM&m=3DOkvFOa7K4fB1QBWJHQgEB73pmn6Idw1HPEA= nKHorrwk&s=3DjobSo3da4u4GsD0TrMWG7CiKqXl6nc4Tx6V0Vuy-J1g&e=3D>* > > > > > > *Regular member* > > *International laboratory for Brain, Music, and Sound Research (BRAMS)* > > *Center for Research on Brain, Language, and Music* > > > > -- > *Leslie R. Bernstein, Ph.D. **| *Professor > Depts. of Neuroscience and Surgery (Otolaryngology)| UConn School of > Medicine > 263 Farmington Avenue, Farmington, CT 06030-3401 > Office: 860.679.4622 | Fax: 860.679.2495 > > > --00000000000075d8ac058a2a6c30 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"auto"><div>Dear Sylvie,</div><div dir=3D"auto"><br></div><div d= ir=3D"auto">I also wondered what you meant by "exceptionally high"= ;? Is that that in previous measures you didn't have this noise? Or is = it that it is high in absolute terms (what are the numbers then)?</div><div= dir=3D"auto"><br></div><div dir=3D"auto">High frequency noise can come fro= m fans, neon lights, screens... Although the latter two tend to have narrow= spectra. Faulty preamp on our sound level meter has also displayed HF nois= e in the past.</div><div dir=3D"auto"><br></div><div dir=3D"auto">-Etienne<= /div><div dir=3D"auto"><br><br><div class=3D"gmail_quote" dir=3D"auto"><div= dir=3D"ltr" class=3D"gmail_attr">On Fri, 31 May 2019, 06:09 Bernstein,Lesl= ie, <<a href=3D"mailto:lbernstein@xxxxxxxx">lbernstein@xxxxxxxx</a>> = wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8e= x;border-left:1px #ccc solid;padding-left:1ex"> <div text=3D"#000000" bgcolor=3D"#FFFFFF"> <font size=3D"-1"><font face=3D"Verdana">Hello--<br> <br> In order to help, much more information is required:<br> <br> Exactly what equipment is it that you wish to calibrate?<br> What equipment are you using or do you have available to make the measures = of the desired signal and the associated noise floor?<br> <br> There are quite a few explanations for what you have found that can be narr= owed down based on the answers to the questions above.=C2=A0 Given reasonab= le assumptions of linearity and availability of precision attenuators, it i= s often not necessary at all to make such measures at low levels.=C2=A0 Whether that's true in your case wi= ll depend upon the details.<br> <br> Les<br> </font></font><br> <br> <div class=3D"m_-8781448731275442526moz-cite-prefix">On 5/30/2019 12:18 AM,= H=C3=A9bert Sylvie wrote:<br> </div> <blockquote type=3D"cite"> <div> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> Dear List,</p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <br> </p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> We would like to calibrate our equipment to verify that it is capable to se= nding low-intensity narrowband noises just above auditory threshold. We hav= e found that the baseline noise levels were exceptionally high for band fre= quencies above 8kHz. Can anyone explain why this may be the case? Does anyone have any suggestions for how= to approach measuring very low-intensity sounds?<u></u><u></u></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <u></u>=C2=A0<u></u></p> </div> <span id=3D"m_-8781448731275442526OLK_SRC_BODY_SECTION"> <div> <div link=3D"blue" vlink=3D"purple" lang=3D"EN-US"> <div class=3D"m_-8781448731275442526WordSection1"> <p class=3D"MsoNormal"><u></u><u></u></p> <p class=3D"MsoNormal">Thanks,</p> </div> </div> </div> </span> <div><br> </div> <div> <div> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b style=3D"font-size:11pt"><span style=3D"font-size:10pt;font-family:Arial= ,sans-serif;color:rgb(35,48,145)">Sylvie H=C3=A9bert,=C2=A0</span></b><b st= yle=3D"font-size:11pt"><span style=3D"font-size:8pt;font-family:Arial,sans-= serif;color:rgb(35,48,145)">Ph.D., Professor</span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b style=3D"font-size:11pt"><span style=3D"font-size:8pt;font-family:Arial,= sans-serif;color:rgb(35,48,145)">School of Speech pathology and audiology</= span></b></p> <p class=3D"MsoNormal" style=3D"margin:0cm 0cm 3pt"><b><span style=3D"font-= size:7pt;font-family:Arial,sans-serif;color:rgb(127,127,127)">Pavillon 7077= , Parc ave. - =C2=A03rd floor=C2=A0 -=C2=A0=C2=A0 room 3001-34<u></u><u></u= ></span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><span style=3D"font-size:9pt;font-family:Arial,sans-serif;color:rgb(35,4= 8,145)">Faculty of medicine=C2=A0</span></b><span style=3D"font-size:9pt;fo= nt-family:Arial,sans-serif;color:rgb(35,48,145)">=C2=A0|=C2=A0<b>Universit= =C3=A9 de Montr=C3=A9al</b></span></p> <table class=3D"m_-8781448731275442526MsoNormalTable" style=3D"color:rgb(0,= 0,0);font-family:Calibri;font-size:14px;border-collapse:collapse" cellspaci= ng=3D"0" cellpadding=3D"0" border=3D"0"> <tbody> <tr style=3D"height:19.7pt"> <td style=3D"width:70.9pt;padding:0cm 5.4pt;height:19.7pt" width=3D"95"> <p class=3D"MsoNormal" style=3D"margin-top:0cm;text-align:center" align=3D"= center"> <a href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttp-3A__www.umontr= eal.ca_&d=3DDwMFAw&c=3DEZxp_D7cDnouwj5YEFHgXuSKoUq2zVQZ_7Fw9yfotck&= amp;r=3D2Pw2GwelGcMR4953G-STHGpPJm2-pYYYSPmTwJk3sWM&m=3DOkvFOa7K4fB1QBW= JHQgEB73pmn6Idw1HPEAnKHorrwk&s=3DSzYSjQbUnlR95fFm1YA1M5QOfS2ztq9rwWYdOM= ngcBQ&e=3D" target=3D"_blank" rel=3D"noreferrer"><span style=3D"color:r= gb(31,73,125);text-decoration:none"><img id=3D"m_-8781448731275442526Image_= x0020_5" src=3D"cid:part1.BA6F76FC.2829C84D@xxxxxxxx" alt=3D"Universit=C3= =A9 de Montr=C3=A9al" type=3D"image/png" width=3D"79" height=3D"31" border= =3D"0"></span></a><span style=3D"font-size:10pt;font-family:Arial,sans-seri= f;color:rgb(31,73,125)"><u></u><u></u></span></p> </td> <td style=3D"width:238.1pt;padding:0cm 5.4pt;height:19.7pt" width=3D"317" v= align=3D"top"> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm"> <span style=3D"margin-left:1px;margin-top:5px;width:295px;height:1px"><img = src=3D"cid:part3.38C987DF.E8C8B595@xxxxxxxx" type=3D"image/png" width=3D"29= 5" height=3D"1"></span><b><span style=3D"font-size:5pt;font-family:Arial,sa= ns-serif;color:rgb(127,127,127)"><u></u><u></u></span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm"> <b><span style=3D"font-size:7pt;font-family:Arial,sans-serif;color:rgb(127,= 127,127)"><br> </span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm"> <b><span style=3D"font-size:7pt;font-family:Arial,sans-serif;color:rgb(127,= 127,127)">Address : c.p. 6128, succ. Centre-ville, Montr=C3=A9al,=C2=A0</sp= an></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm"> <b><span style=3D"font-size:7pt;font-family:Arial,sans-serif;color:rgb(127,= 127,127)">H3C 3J7=C2=A0</span></b><b style=3D"font-size:11pt"><span style= =3D"font-size:7pt;font-family:Arial,sans-serif;color:rgb(127,127,127)">Tel: (514) 343-6111 #2594</span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm"> <b><span style=3D"font-size:6pt;font-family:Arial,sans-serif;color:gray"><a= href=3D"https://urldefense.proofpoint.com/v2/url?u=3Dhttp-3A__www.eoa.umon= treal.ca_&d=3DDwMFAw&c=3DEZxp_D7cDnouwj5YEFHgXuSKoUq2zVQZ_7Fw9yfotc= k&r=3D2Pw2GwelGcMR4953G-STHGpPJm2-pYYYSPmTwJk3sWM&m=3DOkvFOa7K4fB1Q= BWJHQgEB73pmn6Idw1HPEAnKHorrwk&s=3DjobSo3da4u4GsD0TrMWG7CiKqXl6nc4Tx6V0= Vuy-J1g&e=3D" target=3D"_blank" rel=3D"noreferrer"><span style=3D"color= :gray">www.eoa.umontreal.ca</span></a><u></u><u></u></span></b></p> </td> </tr> </tbody> </table> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><span style=3D"font-size:10pt;font-family:Arial,sans-serif">=C2=A0</span= ></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><span style=3D"font-size:9pt;font-family:Arial,sans-serif;color:rgb(35,4= 8,145)">=C2=A0</span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><font face=3D"Arial,sans-serif" color=3D"#233091"><span style=3D"font-si= ze:8pt">R</span></font><font size=3D"2" face=3D"Arial,sans-serif" color=3D"= #233091">e</font><font face=3D"Arial,sans-serif" color=3D"#233091"><span st= yle=3D"font-size:8pt">gular member</span></font></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><span style=3D"font-size:8pt;font-family:Arial,sans-serif;color:rgb(35,4= 8,145)">International laboratory for Brain, Music, and Sound Research (BRAM= S)</span></b></p> <p class=3D"MsoNormal" style=3D"margin-top:0cm;margin-right:0cm;margin-left= :0cm"> <b><span style=3D"font-size:8pt;font-family:Arial,sans-serif;color:rgb(35,4= 8,145)">Center for Research on Brain, Language, and Music</span></b></p> </div> </div> </blockquote> <br> <br> <div class=3D"m_-8781448731275442526moz-signature">-- <br> <b><span>Leslie R. Bernstein, Ph.D. </span></b><b><span>| </span></b><span>Professor</span><span><u></u><u></u></span><span><br> Depts. of Neuroscience and Surgery (Otolaryngology)| UConn School of Medici= ne </span> <br> <span></span><span>263 Farmington Avenue, Farmington, CT 06030-3401</span><br> <span></span><span>Office: 860.679.4622 | Fax: 860.679.2495<br> <br> <img alt=3D"" src=3D"cid:part5.BEEC4A1D.EB39E8C2@xxxxxxxx" width=3D"125" he= ight=3D"48"><br> </span></div> </div> </blockquote></div></div></div> --00000000000075d8ac058a2a6c30-- --00000000000075d8af058a2a6c31 Content-Type: image/png; name="uconnhealth_stacked_blue_email.png" Content-Disposition: inline; filename="uconnhealth_stacked_blue_email.png" Content-Transfer-Encoding: base64 Content-ID: <> X-Attachment-Id: iVBORw0KGgoAAAANSUhEUgAAAH0AAAAwCAMAAAALmIWlAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJ bWFnZVJlYWR5ccllPAAAADNQTFRFKzVYHCZM4eLn8PHzpKi30dTbaG+IlZqrs7fDWWB8O0Nkd32U wsXPSlJwhoufDRhA////A68jmAAAABF0Uk5T/////////////////////wAlrZliAAACYklEQVR4 2uzY22KDIAwAUC7e6gjw/187gUC4OetaupflaTXKWSuBKNMuJptC+QMCP20auPHBQCubBWU46K24 uB7NfZ58ZqaMP8D8AEBHtT/goXnB8WPwBf8r1WYUXWxUOZobHcJXIMcfONclmE4s0lrRzYBIOjvT jX5WV6YbP2ZQJ6TWjfiAbuYzHW7p+xpuolQrP83sjQ5nupnu6LqaJ92MbnSznulcfkBHpNXNY6y+ c0JKnWX1eFeflQt5qcNESKnrQMrf6LSAXeiWkEoXdOU4nZBKxzPnoTohtW5ZZyK8W09Io6tYjyP1 iDS6XbAeh815S0irS6zHUfXuB0Ok1S3W41AdEWh1/Nb7UD1bWytd0LY4ThdnerYbBJ1taT5XBmy4 J8mNnWagp5fbba6HeiTdneK6vNgoFj0EhyO4eSZT6AlpdNXoNzqYi94GbIU0eqhHp3d5drRf4heZ Uo9Iq8vYptup6VB37H6m/W6m0hFpdaxH3/yK9cHpVq5Zy59n2GMV/QxPGdV9NElPE9njyOozsfWW Kq6j7bLuw97KPBnM/mX86//6n+tH/yLKP7AUXcyd80Lx53WnspB47ty5qKND1gLockfIFzHR7srp Q7X0+6GgHPNFXedPyaN1CPFli71z+ZBeTxbcI2RXxwOQj/lW/Ui610Z6gA4a32WRrssXYbO76V/Z y6FLnZVj/qCnqGcdZE1DeFKcntWrMV/RZXCh7B/fpF/+8tQQx6J74y9/Oeuyrm75+Jyf8oKWH9CL 1SYNJtJ91HTOAD2fdjPN9UcsumwmDNYXqvPtOLa9pH8LMACnoV0siZAyOAAAAABJRU5ErkJggg== --00000000000075d8af058a2a6c31--