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From: mnkonar@manyjars.SRC.Honeywell.COM (Murat N. Konar)
Newsgroups: comp.sys.mac
Subject: Re: changing pitch of recorded sounds
Message-ID: <32502@srcsip.UUCP>
Date: 25 Sep 89 23:37:38 GMT
References: <963@babbage.acc.virginia.edu>
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Reply-To: mnkonar@src.honeywell.com (Murat N. Konar)
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In article <963@babbage.acc.virginia.edu> pts@watt.acc.Virginia.EDU (Paul T. Shannon) writes:
>We have a psychoacoustic experiment in which we wish to play short segments of 
>recorded speech, at varying pitches.  For instance, we record a deep male voice
>saying a word, and we want to be able to play that word back at a high pitch.
>
>The pitch-changing tool in MacRecorder (from Farrallon Computing)  is unable
>to preserve the tempo of the original sound: shifting pitch upwards always 
>shortens the duration of the sound, and increases the tempo.
>
>Does anyone know of Mac software that allows us to change pitch *without* 
>changing tempo and duration?

Forgive me for suggesting such a goofy solution but if you can't find the software
you can do this:

Aquire a Yamaha SPX-90 digital effects unit either used or from a music store.
There is a setting on this beast which allows you to shift pitch by an amount
based on a key pressed from a MIDI keyboard.  By sending MIDI information
from the Mac to the SPX-90's MIDI in port and audio from the Mac to the SPX-90's
audio input, you can transpose the audio pitch without affecting tempo or duration.

The downside is the cost of equipment: around $450 or so for a used SPX-90 and
around $70-$100 for a MIDI interface.

Like I said, it's a pretty goofy solution but it will work and the  program
to run the experiment can be set up using Hypercard.  If you need more detail/
better explanation, send me a note.


____________________________________________________________________
Have a day. :^|
Murat N. Konar        Honeywell Systems & Research Center, Camden, MN
mnkonar@SRC.honeywell.com (internet) {umn-cs,ems,bthpyd}!srcsip!mnkonar(UUCP)