[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: changing a sound signal while listening to it
You need continuous real-time synthesis for this. My
Daqarta program can do this easily, and output to a
standard Windows sound card.
Daqarta is not a language like Matlab, it is a stand-alone
application. It has controls hard-wired to control various
features of the signal. You can directly set any control
(like frequency or level), or you can write macros that
automate any set of tasks (like increasing one frequency
and decreasing another by a fixed step size, so the center
remains the same). The macro approach may be better if
your subjects are going to be changing things themselves,
since you can give macros descriptive names that they can
choose from a list, and/or you can assign relevant hot-keys
for convenience. The subject doesn't need to see the 100s
of other controls for modulation, waveshape, etc.
Daqarta also shows you the spectrum, waveform, or
spectrogram of the generated sound in real time, so you can
see the effects of the changes as well as hear them.
You can download and try Daqarta for 30 days/30 sessions.
After that, you can't store new macros, or analyze signals
from the sound card input channels (though you can still
analyze the outgoing signals), but everything else
continues to work forever... you might not need to buy it
As it happens, I will be off-line for a week or two
starting tomorrow. If you have any questions, I'll be glad
to help today or afterward.
On 10 Aug 2010 at 10:32, Daniel Bowling wrote:
> Dear List,
> I am trying to create a piece of software that will allow a subject to
> change the beat frequency and amplitude of a signal while listening to it in
> real time.
> More specifically, the signal will consist of two pure tones (e.g. T1 + T2),
> and the difference between them (T2 - T1) as well as the root mean square
> amplitude will be under the control of the subject via the keyboard.
> I have tried to execute this in Matlab using a loop, the problem is that the
> sound stops and then starts again at the beginning of each loop iteration.
> Can anyone suggest a way this might be implemented on a computer? Or perhaps
> just a suitable programming language?
> Dan Bowling
D A Q A R T A
Data AcQuisition And Real-Time Analysis
Scope, Spectrum, Spectrogram, Signal Generator
Science with your sound card!