This is, for better or worse, rather a large topic! Several primary
questions immediately arise:

How different are the two target sounds?
How much does each sound change over time?
What is the definition of the 'middle sound'?

For example, what is the middle sound between a violin scale and a siren,
or a flute and a bell?

Do you want the sound to be 'technically' in the middle (such as the
continuous difference of the two spectra), or, somehow, 'intuitively' in
the middle?

For example, intuitively, the middle sound between a cello and a violin
might be a viola, but technically it might be something that is neither
cello, violin nor viola.

All the research I have read on this topic suggests that there is not a
simple linear timbral relationship betweeen two sounds; rather, sounds
live in a 'timbre-space' which is at least three-dimensional.

[extend neck]
So far as I can tell, there are as yet no definitive or conclusive answers
to any of these questions!  It may also,be that in principle such a middle
sound cannot be found in real-time, as the algorithm would need to look
ahead to sound which has yet to arrive.
[withdraw neck again]


Richard Dobson


Qian Chen wrote:

> Hi,
>
> There was something wrong in my previous message
>
> > I think there will be 3 conditions:
> >    sampled sound 1-> middle timbre sampled sound -> sampled sound 2
> >    sound generated by Csound -> sampled sound
> >    sampled sound -> sound generated by Csound
>
> should be
>      1. sampled sound 1-> middle timbre -> sampled sound 2
>      2. sound generated by Csound -> middle timbre -> sampled sound
>      3. sampled sound -> middle timbre -> sound generated by Csound
>
> What I would like to add is that the _sampled sound_ should have been
> sampled and exists on the hard disk, while _sound generated by Csound_
> is the sound generated dynamically by Csound, which means this sound
> does not exists on the hard disk.
>
> Sorry for disturbing you again.
>
> ==
> Qian Chen
>
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