Psychtoolbox: How to play selected audio files?

I would like to play Beep and selected audion files alternately.

How should I write a code to play selected audio files?

I have a code to play all audio files randomly but I want to play only selected files and not randomely.

% Code for Audio multiple files read
    audio_files=dir('C:\toolbox\aud_file2\*.wav');

% initializes sound driver...the 1 pushes for low latency
    InitializePsychSound(1);

% opens sound buffer at a different frequency
    pahandle = PsychPortAudio('Open', [], [], 2, []);

%randomize
    a=randperm(80);

    for i=1:length(audio_files)
        % load sound file (make sure that it is in the same folder as this script)
        [soundData freq  ] = audioread('Beep1000convert.mp3');

        % loads data into buffer
        PsychPortAudio('FillBuffer', pahandle, soundData');

        % how many repititions of the sound
        repetitions=1;

        %starts sound immediatley
        PsychPortAudio('Start', pahandle, repetitions,0);

        % stop
        PsychPortAudio('Stop', pahandle, 1,0);

        % load sound file (make sure that it is in the same folder as this script)
        aud_file=strcat('C:\toolbox\aud_file2\',audio_files(a(i)).name);
        [soundData freq]=audioread(aud_file);

        % wait
        rs = randperm(3);
        WaitSecs(2.0);
        % fill buffer
        PsychPortAudio('FillBuffer', pahandle, soundData');

        % starts sound immediatley
        PsychPortAudio('Start', pahandle, 1,0);

        % stop
        PsychPortAudio('Stop', pahandle, 1,0);

[Mathieu NOE]

hi

well, I see two simple answers :

• either keep only the selected audio files in the current directory
• or make a list of the selected files (instead of audio_files=dir('C:\toolbox\aud_file2\*.wav'); ) and loop through that list , either randomly or not

[Takara Sumoto]

Thank you for the suggestion.

[Mathieu NOE]

hello

see example below

if you want to loop automatically through the directory (all files) , you can do like this :

% method for looping through all files in directory 
file = dir ('*.wav');
M= length (file)


%%%%%%%%%%%
NFFT = 512;    
NOVERLAP = round(0.75*NFFT);
w = hamming(NFFT);
%%%%%%%%%%%

for ck = 1:M
    
     [data,Fs]= audioread(file(ck).name);

     [sensor_spectrum, freq] = pwelch(data,w,NOVERLAP,NFFT,Fs);
     
     figure(ck),plot(freq,20*log10(sensor_spectrum));
     title(['Spectra  / Fs = ' num2str(Fs) ' Hz / Delta f = ' num2str(freq(2)-freq(1)) ' Hz  ']);
     xlabel('Time (s)');ylabel('Frequency (Hz)');

end

if you want to creat a short list manually you can do (old fashioned way but still works ) :

% method for looping through manual  files list
% file names = strings 
% make sure to have all strings same length (add trailling blank for shorter names)
file(1,:) = 'Approach_Gear_Drop_Aft Ctr.wav';  
file(2,:) = 'Approach_Gear_Drop_Aft LH.wav ';   
file(3,:) = 'Approach_Gear_Drop_Aft RH.wav '; 
M = 3;

%%%%%%%%%%%
NFFT = 512;    
NOVERLAP = round(0.75*NFFT);
w = hamming(NFFT);
%%%%%%%%%%%

for ck = 1:M
    
     [data,Fs]= audioread(file(ck,:));

     [sensor_spectrum, freq] = pwelch(data,w,NOVERLAP,NFFT,Fs);
     
     figure(ck),plot(freq,20*log10(sensor_spectrum));
     title(['Spectra  / Fs = ' num2str(Fs) ' Hz / Delta f = ' num2str(freq(2)-freq(1)) ' Hz  ']);
     xlabel('Time (s)');ylabel('Frequency (Hz)');

end

[Takara Sumoto]

Thank you for your suggestion!