Re: Modifying speech signal

[Matt Davis <Matt.Davis@xxxxxxxxxxxxxxxxx>]

Dear David,
> For a study of formant perception, I'm seeking a method to transform  
> normal speech signals so as to alter the apparent vocal tract length  
> of the speaker. Any and all suggestions much appreciated.
>   
There are a couple of pieces of software that you can use for this.

1) Hideki Kawahara's "Straight" software which runs in Matlab does a 
good job of this. However, since Straight is not freely available, 
you'll need to send an email to Hideki to request access to the code:

http://www.wakayama-u.ac.jp/~kawahara/index-e.html

2) Easier to access (and perhaps more straightforward to use) is Praat:

http://www.praat.org

There's a built in function in recent versions of the software to 
"change gender", which shifts formants with or without changing pitch 
and that produces good quality output.

hope one or other of these does the job.

best wishes,

matt



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 Dr Matt Davis
 MRC Cognition and Brain Sciences Unit
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