I'm not sure what the right newsgroup is for this question, but it certainly
involves mathematics and probably involves numerical mathematics in some
implementations.

I used to hear recordings of music in which a singer somehow managed to
give his voice a guitar timbre by some kind of mixing of a signal representing
his voice and a signal representing the guitar. I would like to know what
mathematical operation is being applied to the two signals to produce
this effect?

On Mar 9, 2:26 pm, Allan Adler <a...@nestle.csail.mit.edu> wrote:

I'm not sure what the right newsgroup is for this question, but it
certainly
involves mathematics and probably involves numerical mathematics in some
implementations.

comp.dsp might be a better bet. The thing you seek is a vocoder.
Various 70's rock bands like ELO specialised in having some parts done
this way. DSP implementations for PC & Mac exist.
eg http://en.wikipedia.org/wiki/Vocoder
Same for ring modulators that give cybermen their distinctive twang.

I used to hear recordings of music in which a singer somehow managed to
give his voice a guitar timbre by some kind of mixing of a signal
representing
his voice and a signal representing the guitar. I would like to know what
mathematical operation is being applied to the two signals to produce
this effect?

A combination of many bandpass filters and combining the amplitude
envelope of the speech with the musical content of the guitar (with
various tricks to make the result acceptable).
I chased after your link and found myself downloading a .ogg file. What

I'm not sure what the right newsgroup is for this question, but it certainly
involves mathematics and probably involves numerical mathematics in some
implementations. I used to hear recordings of music in which a singer
somehow managed to give his voice a guitar timbre by some kind of mixing
of a signal representing his voice and a signal representing the guitar.
I would like to know what mathematical operation is being applied to the
two signals to produce this effect?

Allan Adler <a...@nestle.csail.mit.edu> writes:
I'm not sure what the right newsgroup is for this question, but it certainly
involves mathematics and probably involves numerical mathematics in some
implementations. I used to hear recordings of music in which a singer
somehow managed to give his voice a guitar timbre by some kind of mixing
of a signal representing his voice and a signal representing the guitar.
I would like to know what mathematical operation is being applied to the
two signals to produce this effect?

Thanks for the helpful replies. The term "vocoder" made it possible for me
use Google and led me to some free software that runs under Linux that I can
study, namely vocoder-0.5.14. I already looked over the source code and it
seems pretty straightforward.
--
Ignorantly,
Allan Adler <a...@zurich.csail.mit.edu
* Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My actions and
* comments do not reflect in any way on MIT. Also, I am nowhere near Boston.

On Mar 10, 12:20 am, Allan Adler <a...@nestle.csail.mit.edu> wrote:
Allan Adler <a...@nestle.csail.mit.edu> writes:
I'm not sure what the right newsgroup is for this question, but it
certainly
involves mathematics and probably involves numerical mathematics in
some
implementations. I used to hear recordings of music in which a singer
somehow managed to give his voice a guitar timbre by some kind of
mixing
of a signal representing his voice and a signal representing the
guitar.
I would like to know what mathematical operation is being applied to
the
two signals to produce this effect?

Thanks for the helpful replies. The term "vocoder" made it possible for
me
use Google and led me to some free software that runs under Linux that I
can
study, namely vocoder-0.5.14. I already looked over the source code and
it
seems pretty straightforward.
--
Ignorantly,
Allan Adler <a...@zurich.csail.mit.edu
* Disclaimer: I am a guest and *not* a member of the MIT CSAIL. My
actions and
* comments do not reflect in any way on MIT. Also, I am nowhere near
Boston.

just a mote:
what you may have heard may have been created by a mechanical system,
consisting of a hose or a tube that runs from a guitar
amplifier speaker up to a few inches from the microphone
the singer holds the end of the tube in his mouth and by
mouthing words creates the effect
Peter Frampton's "Do you Feel" comes to mind.