[no subject]

[Tom Walters <tomwalters@xxxxxxxxxx>]

Brittany,
If you look at voice production from the source-filter perspective, a
pitch change corresponds to a change in the sampling of the spectral
envelope. The spectral envelope itself is a function of the
configuration and length of the vocal tract. As the pitch increases,
the spectral envelope becomes more sparsely sampled by the harmonics
of the driving pulse train, so in that sense information is lost as
pitch increases. A five-semitone increase in the pitch corresponds to
changing the density of sampling of the spectral envelope by a factor
of about 3/4  (1/(2^(5/12)). The train of harmonics also rises in
frequency, of course, so some will be lost 'off the top' of the
spectrum, however this is probably a negligible effect - more
important is the change in she sampling density of the envelope.

The (cartoon, idealized) figures on this page might help visualize
what's going on in the time domain and the frequency domain as the
pitch changes:
http://www.acousticscale.org/wiki/index.php/Acoustic_Scale_in_Communication_Sounds#Size_Information_and_Acoustic_Scale_in_Communication_Sounds

Cheers

Tom

On 2 September 2011 12:27, Brittany Guidone <brittanyguidone@xxxxxxxxx> wrote:
> Dear List,
>
> Can anyone tell me what systemally happens to a males voice when the pitch
> of it is increased byÂfive semi tones? Is any information lost? Or are the
> frequencies too high for humans to be able to hear all of the components of
> that the original voice contains when the voice's pitch is altered? I
> somewhat understand the pitch, but I am unable to understand what actually
> happens to a human voice when the pitch is changed by a number of semi
> tones. If anyone knows about pitch change how humans percieve pitch changes
> I would be interested in knowing.
>
> Thank you,
> Brittany Guidone