Pierre - I don't think you can dynamically change the frequency even if using the audioplayer. I think that you could use one player and wait for it to stop before applying the frequency change and then restart the player so that it plays at the new frequency. For example, the following code will play a signal at an initial frequency and continue to play it (at that frequencey or another) until the user stops (by pressing 'x').
function AudioPlayerFrequencyExample
close all;
% initialize the audioplayer
durationSec = 2;
Fs = 8000;
t = linspace(0,durationSec,durationSec*Fs);
frqHz = 100;
Y = sin(2*pi*frqHz*t);
audioPlayer1 = audioplayer(Y,Fs);
stopAudioForAlways = false;
freqDeltaHz = 0;
% create the figure and assign the callback
hFig = figure;
set(hFig,'WindowKeyPressFcn',@keyPressCallback);
function keyPressCallback(~,eventdata)
% start the player if needed
if ~isplaying(audioPlayer1)
restartAudioPlayerIfStopped();
end
% determine the key that was pressed
keyPressed = eventdata.Key;
if strcmpi(keyPressed,'uparrow')
% increase the frequency by 10 Hz
freqDeltaHz = 10;
elseif strcmpi(keyPressed,'downarrow')
% decrease the frequency by 10 Hz
freqDeltaHz = -10;
elseif strcmpi(keyPressed,'x')
% stop the player
stopAudioForAlways = true;
end
end
function restartAudioPlayerIfStopped(~, ~)
% restart the player at the (possibly) new frequency
if ~stopAudioForAlways
frqHz = frqHz + freqDeltaHz;
Y = sin(2*pi*frqHz*t);
freqDeltaHz = 0;
audioPlayer1 = audioplayer(Y,Fs);
audioPlayer1.StopFcn = @restartAudioPlayerIfStopped;
play(audioPlayer1);
end
end
end
Note that there is a pause when the player stops and then restarts at a different frequency. I tried experimenting with two players so that I could start one and then stop the running player but noticed a clicking (static) sound during the transition.
