Subject: Re: [AUDITORY] Chirps with Cochlear Delay From: Marc Schoenwiesner <marcs@xxxxxxxx> Date: Wed, 18 Jan 2023 21:22:24 +0100--Apple-Mail=_D4A4385A-2C39-4B27-94B8-0374DB7BA343 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Dear Andrew, dear all, since this might be interesting to others as well, I=E2=80=99m replying = to the list: I used Torsten Dau=E2=80=99s optimal chirp about 20 years ago in am MEG = experiment and had asked him about a Matlab implementation, which he = kindly shared under a license that allows distribution. Please find it = attached. Since it is now archived on the list server, it will hopefully = remain accessible in the future. A Python reimplementation will also be = available in the slab toolbox in a week or two. Cheers, Marc --Apple-Mail=_D4A4385A-2C39-4B27-94B8-0374DB7BA343 Content-Disposition: attachment; filename=bmchirp.m Content-Type: application/octet-stream; x-unix-mode=0777; name="bmchirp.m" Content-Transfer-Encoding: quoted-printable function=20sig=20=3D=20bmchirp(f1,f2,fs,len,flat)=0D=0A%=20=20BMCHIRP=20= generates=20optimized=20Chirp=20described=20in=20Dau=20et=20al.=20(2000)=0D= =0A%=0D=0A%=09sig=20=3D=20bmchirp(f1,f2,fs,len,flat)=0D=0A%=09generates=20= the=20``approximated''=20optimized=20chirp=20developed=20by=20Dau=20et=20= al.=0D=0A%=09(2000).=20This=20chirp=20compensates=20for=20travel-time=20= differences=20along=20the=0D=0A%=09cochlear=20partition.=20The=20= equations=20were=20derived=20on=20the=20basis=20of=20a=20linear=0D=0A%=09= cochlea=20model=20(de=20Boer,=201980).=0D=0A%=0D=0A%=09A=20vector=20sig=20= is=20returned.=20The=20vector=20is=20filled=20with=20zeros=20to=20match=20= the=0D=0A%=09length=20of=20len.=20If=20len=20equals=20zero=20the=20= 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distribute=20this=20software/file=20and=20its=0D=0A%%=09documentation=20= for=20any=20purpose=20without=20permission=20by=20the=20author=0D=0A%%=09= is=20strictly=20forbidden.=0D=0A%%=0D=0A%%=09Permission=20to=20modify=20= the=20software=20is=20granted,=20but=20not=20the=20right=20to=0D=0A%%=09= distribute=20the=20modified=20code.=0D=0A%%=0D=0A%%=09This=20software=20= is=20provided=20"as=20is"=20without=20expressed=20or=20implied=20= warranty.=0D=0A%%=0D=0A%%=0D=0A%%=09AUTHORS=0D=0A%%=0D=0A%%=09=09Torsten=20= Dau=20/=20Oliver=20Fobel=0D=0A%%=09=09Acoustic=20Technology,=20= =D8rsted=B7DTU=0D=0A%%=09=09Centre=20for=20Applied=20Hearing=20Research=0D= =0A%%=09=09Technical=20University=20of=20Denmark,=20Building=20352=0D=0A= %%=09=09=D8rsteds=20Plads=0D=0A%%=09=09DK-2800=20Kgs.=20Lyngby=0D=0A%%=09= =09Denmark=0D=0A%%=0D=0A%%=09=09e-mail:=09=09tda@xxxxxxxx=0D=0A%%=09= =09=09=09of@xxxxxxxx=0D=0A%%=0D=0A= %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%= %%%%%=0D=0A= --Apple-Mail=_D4A4385A-2C39-4B27-94B8-0374DB7BA343 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Dean, Dept of Life Sciences Professor of Neurobiology Department of Biology University of Leipzig Talstrasse 33 __o 04103 Leipzig _`\<,_ +493419736723 (+) / (+) & Department of Psychology University of Montreal Montreal, Quebec, Canada www.uni-leipzig.de/~neuro/ =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > On 17. Jan 2023, at 23:29, Andrew Levitsky <alevitsk@xxxxxxxx> = wrote: >=20 > Hello Auditory List, >=20 > I have been working on a masked ABR experiment and wanted to generate = a chirp that compensated for basilar membrane traveling wave delay, akin = to what was discussed in the 2010 Chertoff = (https://asa.scitation.org/doi/full/10.1121/1.3372756) and 2004 Fobel & = Dau (https://asa.scitation.org/doi/pdf/10.1121/1.1787523) articles. = While the articles do include the formulas that they used, I am not sure = how to actually apply said formulas in Matlab, or if they are compatible = with the built-in chirp function that Matlab has. Does anyone have any = advice for generating them in our script? >=20 > Thank you, > Andrew >=20 > --=20 > Andrew Levitsky > Research Associate > Carnegie Mellon Neuroscience Institute > alevitsk@xxxxxxxx > M: (908) 420-9917 --Apple-Mail=_D4A4385A-2C39-4B27-94B8-0374DB7BA343--