Re: Audibility of frequency notches

[Sheila M Williams <sheila.williams@xxxxxxxxx>]

Hi,

doesn't this depend on where the notch is with respect to the speech
signal, the overall spectral pattern of the speech signal and whether
things such as fundamental frequency are changing over time?

The speech signal is very complex and the significant information in it is
context dependent (e.g. frication range of fricatives, formant peaks for
vowels etc.), different fom speaker to speaker, and changing all the time.
I would guess you could remove almost anything that wasn't providing the
relevant cues at any given time and no-one would notice.

Sheila Williams

At 02:02 PM 16/1/02 -0500, David I. Havelock wrote:
>List members
>
>A colleague here has been looking for an answer to the following question...
>
>Consider speech with a frequency band removed, such as might be done with an
>ideal notch filter. It seems that if the removed band is very narrow then
>there is no perceived degradation in the speech. How wide must the removed
>frequency band be before a degradation in the speech becomes  noticable?
>
>Is the answer to this known?
>
>David Havelock
>----------------------------------
>David I. Havelock
>Acoustics and Signal Processing Group
>Institute for Microstructural Sciences, M-36
>National Research Council (Canada)
>1200 Montreal Road, Ottawa, ON, K1A 0R6
>david.havelock@nrc.ca
>voice: (613) 993-7661   fax: (613)952-3670
>45N27'16" 75E37'26"
>
>

Sheila Williams                              Tel 020 7679 5399
Psychology Department                        Fax 020 7436 4276
University College London
26 Bedford Way
London WC1H 0AP
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