Sure, this is absolutely correct in a musical context. So, let's agree
on expanding the original definition a bit by including the case of
abruptly changing parameters during playing of the instrument to also
produce transients. That would include volume, pitch etc. and should
give us what we need. :-)

I think we should omit the attack/decay/sustain/release phase
discussion altogether since it's a definition coined by the music
industry to label playback phases when simulating instruments. Since
they usually treat successive notes separately for technical reasons,
the transition between notes isn't actually a problem - the release
phase of the old note would be where the attack phase of the new note
is...

And I'd say that for the definition of "transient" the playback phase
isn't relevant anyway.

--smb


Jerry Avins <jya@ieee.org> wrote:
> But Stephan, That is how a piano is normally played. It's the sound
> we've come to expect. Whether it's best thought of an ending transient
> or a new attack would be an interesting discussion over a glass of beer.
> Of course, pianos have sustain pedals, but releasing the pedal damps
> many notes simultaneously. Even guitar and viol strings are rarely
> allowed to decay completely before the next notes on them are played.
> Consider even a trill on a flute. There is only one air column, so one
> note must stop as abruptly as the other note starts.
> 
> Jerry

Stephan M. Bernsee wrote:

> Yes Jerry, but that wasn't my point. Of course you can actively stop
> almost *any* instrument, in which case you might get an additional
> transient (since you're actually "hitting" the instrument again, this
> could even be seen as a new attack phase!). I was talking about the
> natural release phase of instruments, usually it does not involve any
> action other than stopping the excitation.
> 
> --smb

But Stephan, That is how a piano is normally played. It's the sound
we've come to expect. Whether it's best thought of an ending transient
or a new attack would be an interesting discussion over a glass of beer.
Of course, pianos have sustain pedals, but releasing the pedal damps
many notes simultaneously. Even guitar and viol strings are rarely
allowed to decay completely before the next notes on them are played.
Consider even a trill on a flute. There is only one air column, so one
note must stop as abruptly as the other note starts.

Jerry

> Jerry Avins <jya@ieee.org> wrote in message news:<40c89433$0$3032$61fed72c@news.rcn.com>...
> 
>>Stephan M. Bernsee wrote:
>>
>>   ...
>>
>>
>>>I see your point, although I can't think of many instruments where
>>>this would apply. The only example that I can think of right now is an
>>>electric organ and probably a harpsichord. Most instruments have a
>>>relatively slow release and are not actively stopped. Even for
>>>woodwind instruments the air column continues to oscillate for a few
>>>cycles before the resonance finally breaks down.
>>
>>Piano, when the damper is applied. Kettle drum when stopped by hand.
>>Cymbals, when the pedal is released.
>>
>>Jerry

Yes Jerry, but that wasn't my point. Of course you can actively stop
almost *any* instrument, in which case you might get an additional
transient (since you're actually "hitting" the instrument again, this
could even be seen as a new attack phase!). I was talking about the
natural release phase of instruments, usually it does not involve any
action other than stopping the excitation.

--smb

Jerry Avins <jya@ieee.org> wrote in message news:<40c89433$0$3032$61fed72c@news.rcn.com>...
> Stephan M. Bernsee wrote:
> 
>    ...
> 
> > I see your point, although I can't think of many instruments where
> > this would apply. The only example that I can think of right now is an
> > electric organ and probably a harpsichord. Most instruments have a
> > relatively slow release and are not actively stopped. Even for
> > woodwind instruments the air column continues to oscillate for a few
> > cycles before the resonance finally breaks down.
> 
> Piano, when the damper is applied. Kettle drum when stopped by hand.
> Cymbals, when the pedal is released.
> 
> Jerry

"Jon Harris" wrote:
> That sounds right.  FYI, here are a couple of web sites that have screen shots
> of CoolEdit's Spectral view:
> http://www.worlditc.org/k_03_filtering_of_voices.htm
> http://kerouac.pharm.uky.edu/seti/experiments/cool_doppler/Cool_doppler.htm

yes that definitely looks like a spectrogram display.

--smb

"Stephan M. Bernsee" <stephan.bernsee@web.de> wrote in message
news:38ab652c.0406100016.5c16326a@posting.google.com...
> "Jon Harris" <goldentully@hotmail.com> wrote:

> > You are probably right about this.  Is there a common name for a color-coded
> > spectrum plot like is used in CoolEdit (takes short term FFTs, horizontal
axis
> > represents time, vertical axis represents frequency, color represents
intensity
> > of that frequency)?
>
> The trouble is I can't use Cooledit since I'm primarily on the Mac, so
> I don't know what kind of display this is. I would guess from your
> description that it's a spectrogram.

That sounds right.  FYI, here are a couple of web sites that have screen shots
of CoolEdit's Spectral view:
http://www.worlditc.org/k_03_filtering_of_voices.htm
http://kerouac.pharm.uky.edu/seti/experiments/cool_doppler/Cool_doppler.htm

Stephan M. Bernsee wrote:

   ...

> I see your point, although I can't think of many instruments where
> this would apply. The only example that I can think of right now is an
> electric organ and probably a harpsichord. Most instruments have a
> relatively slow release and are not actively stopped. Even for
> woodwind instruments the air column continues to oscillate for a few
> cycles before the resonance finally breaks down.

Piano, when the damper is applied. Kettle drum when stopped by hand.
Cymbals, when the pedal is released.

Jerry
-- 
Engineering is the art of making what you want from things you can get.
�����������������������������������������������������������������������

"Jon Harris" <goldentully@hotmail.com> wrote:
> Some instruments have a "transient" or percussive release.  I think some
> electric organs have a "click" on release.  ....  Many instruments are actively
> stopped.

I see your point, although I can't think of many instruments where
this would apply. The only example that I can think of right now is an
electric organ and probably a harpsichord. Most instruments have a
relatively slow release and are not actively stopped. Even for
woodwind instruments the air column continues to oscillate for a few
cycles before the resonance finally breaks down.

But I agree, an abrupt release would also produce a transient.

> You are probably right about this.  Is there a common name for a color-coded
> spectrum plot like is used in CoolEdit (takes short term FFTs, horizontal axis
> represents time, vertical axis represents frequency, color represents intensity
> of that frequency)?

The trouble is I can't use Cooledit since I'm primarily on the Mac, so
I don't know what kind of display this is. I would guess from your
description that it's a spectrogram.

--smb

"Stephan M. Bernsee" <stephan.bernsee@web.de> wrote in message
news:38ab652c.0406082215.6da4a187@posting.google.com...
> "Jon Harris" <goldentully@hotmail.com> wrote:
> > Well transients are usually the things that don't show up in standard
frequency
> > analysis!
>
> Well, actually they do! It's just that the "standard frequency
> analysis" (I assume you're talking about the Fourier transform here?)
> isn't very good at representing them in a manner that makes them easy
> to see in a spectrogram. Their energy contributes to many of the DFT
> bins which is why they appear as a "smear" across the frequency axis.

Yes, that is what I meant.  Good clarification.

> > They are usually the "starts" and "stops" of signals, or in musical
> > terms, the attack and release.
>
> I'm not sure if the release phase really qualifies to be a transient.
> Usually, it's quite long (compared to the attack) and generally
> contains relatively steady-state partials. Even for drums, the release
> phase contains the decaying resonances of the instrument, which are
> often quite periodic.
>
> But maybe we disagree on the term release here: I consider "release"
> to be the decaying output that is observed after I stop providing
> energy to the excitation mechanism of the instrument. I don't think
> that actively stopping the instrument as you suggest (by muting the
> strings of a guitar with your hand) can be called a "release phase".

Some instruments have a "transient" or percussive release.  I think some
electric organs have a "click" on release.  You are correct that many
instruments have a slowly decaying release, but for some I would call this a
transient.  I'm not sure why actively stopping an instrument wouldn't be
considered the release phase.  Many instruments are actively stopped.  Back in
the days of the ADSR (attack decay sustain release) model, I thought the whole
point of the release phase was to model releases that ranged from fairly slow
decays to very abrupt (transient) cut-offs.

> > It's called Spectral view in CoolEdit, or sometimes I think it is
> > called a voice print.
>
> I think a "voice print" is something else, more like a long term
> spectrum of a voice to identify (or verify) the speaker of a message
> in the context of security.

You are probably right about this.  Is there a common name for a color-coded
spectrum plot like is used in CoolEdit (takes short term FFTs, horizontal axis
represents time, vertical axis represents frequency, color represents intensity
of that frequency)?

"Jon Harris" <goldentully@hotmail.com> wrote:
> Well transients are usually the things that don't show up in standard frequency
> analysis! 

Well, actually they do! It's just that the "standard frequency
analysis" (I assume you're talking about the Fourier transform here?)
isn't very good at representing them in a manner that makes them easy
to see in a spectrogram. Their energy contributes to many of the DFT
bins which is why they appear as a "smear" across the frequency axis.

> They are usually the "starts" and "stops" of signals, or in musical
> terms, the attack and release. 

I'm not sure if the release phase really qualifies to be a transient.
Usually, it's quite long (compared to the attack) and generally
contains relatively steady-state partials. Even for drums, the release
phase contains the decaying resonances of the instrument, which are
often quite periodic.

But maybe we disagree on the term release here: I consider "release"
to be the decaying output that is observed after I stop providing
energy to the excitation mechanism of the instrument. I don't think
that actively stopping the instrument as you suggest (by muting the
strings of a guitar with your hand) can be called a "release phase".

> It's called Spectral view in CoolEdit, or sometimes I think it is
> called a voice print.

I think a "voice print" is something else, more like a long term
spectrum of a voice to identify (or verify) the speaker of a message
in the context of security.

--smb

I realized that soon after I posted it, so I posted again explaining
in more detail. I will be more observant in the future.

--smb

"Jon Harris" <goldentully@hotmail.com> wrote:
> Works for me, but interestingly gives the exact same definition that the OP's
> first post listed:
> 
> So it's not too helpful since the OP already knows that!