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Re: Granular synthesis and auditory segmentation

Richard J. Fabbri wrote:
>         ... Didier's example of listening to a Halfwave Sine vs a Sine is
>         not equivalent to the transduction function provided by the
>         neural HALFwave action caused by a neural refractory period
>         when the acoustic waveform is of the opposite polarity.

I agree that Didier's example of listening to a half-wave rectified
tone is different from half-wave rectification in transduction. Didier
had suggested listening to the half-wave rectified waveform and hearing
the difference (I think many of us misinterpreted what you had said
initially; I think he was offering a counterexample constructed out of
what he thought was your logic).

Irrespective of the relevance or irrelevance of Didier's suggestion
to what you believe, if you actually listen to the half-wave rectified
waveform (mine was a 1 kHz pure tone),
it (unexpectedly)  doesn't sound all that
different from the unrectified version, despite the addition of
extra components in the power spectrum.

There may be a reason for this -- when you look
at the form of the autocorrelation functions of the two signals,
rectified and unrectified, they are very similar.
So it is also for peak-clipped speech.

My general point here is that how various nonlinearities play themselves
out perceptually depends critically on the nature of the
neural representations that the auditory system uses
to subserve those percepts. We need to be
more self-conscious about our neural coding assumptions.

So, I agree, we are all talking about different things here.

Peter Cariani

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