See this demo. Save it as make_wav_file.m.
% Program to create a warbling wave file with variable amplitude and pitch.
function make_wav_file()
% Initialization / clean-up code.
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 20;
% Create the filename where we will save the waveform.
folder = pwd;
baseFileName = 'Test_Wave.wav';
fullFileName = fullfile(folder, baseFileName);
fprintf('Full File Name = %s\n', fullFileName);
% Set up the time axis:
t = 1:15000;
% Set up the period (pitch, frequency):
T = 13;
T = linspace(25, 8, length(t)); % Pitch changes.
% Create the maximum amplitude:
Amplitude = 32767;
% Add an exponential decay:
Amplitude = Amplitude .* exp(-0.0003*t);
% Add an ocillation on the amplitude:
% Amplitude = Amplitude .* rand(1, length(x)); % Makes a shushing/roaring sound.
Amplitude = Amplitude .* sin(2.*pi.*t./2000); % Decaying pulsing sound.
% Construct the waveform:
y = int16(Amplitude .* sin(2.*pi.*t./T));
% y = abs(int16(Amplitude .* sin(2.*pi.*x./T)));
% Plot the waveform:
plot(t, y, 'b-');
title('Waveform', 'FontSize', fontSize);
xlabel('Time', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);
grid on;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
fprintf('Writing file %s...\n', fullFileName);
% Write the waveform to a file:
wavwrite(y, fullFileName);
% Play the sound as many times as the user wants.
playAgain = true;
counter = 1;
while playAgain
% Play the sound that we just created.
fprintf('Playing file %s %d times...\n', fullFileName, counter);
PlaySoundFile(folder, baseFileName);
% Ask user if they want to play the sound again.
promptMessage = sprintf('You have played the sound %d times.\nDo you want to play the sound again?', counter);
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'Yes', 'No', 'Yes');
if strcmpi(button, 'No')
playAgain = false;
break;
end
counter = counter + 1;
end
% Alert user that we are done.
message = sprintf('Done playing %s.\n', fullFileName);
fprintf('%s\n', message);
promptMessage = sprintf('Done playing %s.\nClick OK to close the window\nor Cancel to leave it up.', fullFileName);
titleBarCaption = 'Continue?';
button = questdlg(promptMessage, titleBarCaption, 'OK', 'Cancel', 'OK');
if strcmpi(button, 'OK')
close all; % Close down the figure.
end
%================================================================================================
% Play a wav file. You can pass in 'random' and it will pick one at random from the folder to play.
% PlaySoundFile(handles.soundFolder, 'chime.wav');
% PlaySoundFile(handles.soundFolder, 'random');
function PlaySoundFile(soundFolder, baseWavFileName)
global waveFileData;
global Fs; % Wave file information.
try % Read the sound file into MATLAB, and play the audio.
% soundFolder = fullfile(soundFolder, 'Sound Files');
if ~exist(soundFolder, 'dir')
warningMessage = sprintf('Warning: sound folder not found:\n%s', soundFolder);
WarnUser(warningMessage);
return;
end
if strcmpi(baseWavFileName, 'random')
itWorked = false;
tryCount = 1;
while itWorked == false
% Pick a file at random.
filePattern = fullfile(soundFolder, '*.wav');
waveFiles = dir(filePattern);
numberOfFiles = length(waveFiles);
% Get a random number
fileToPlay = randi(numberOfFiles, 1);
baseWavFileName = waveFiles(fileToPlay).name;
fullWavFileName = fullfile(soundFolder, baseWavFileName);
waveFileData = -1;
try
if exist(fullWavFileName, 'file')
[waveFileData, Fs, nbits, readinfo] = wavread(fullWavFileName);
sound(waveFileData, Fs);
% soundsc(y,Fs,bits,range);
else
warningMessage = sprintf('Warning: sound file not found:\n%s', fullWavFileName);
WarnUser(warningMessage);
end
% It worked. It played because the audio format was OK.
itWorked = true;
catch
% Increment the try count and try again to find a file that plays.
tryCount = tryCount + 1;
if tryCount >= numberOfFiles
break;
end
end
end % of while()
else
% baseWavFileName = 'Chime.wav';
fullWavFileName = fullfile(soundFolder, baseWavFileName);
waveFileData = -1;
if exist(fullWavFileName, 'file')
[waveFileData, Fs, nbits, readinfo] = wavread(fullWavFileName);
sound(waveFileData, Fs);
% soundsc(y,Fs,bits,range);
else
warningMessage = sprintf('Warning: sound file not found:\n%s', fullWavFileName);
WarnUser(warningMessage);
end
end
catch ME
if strfind(ME.message, '#85')
% Unrecognized format. Play chime instead.
fprintf('Error in PlaySoundFile(): %s.\nUnrecognized sound format in file:\n\n%s\n', ME.message, fullWavFileName);
baseWavFileName = 'Chime.wav';
fullWavFileName = fullfile(soundFolder, baseWavFileName);
waveFileData = -1;
if exist(fullWavFileName, 'file')
[waveFileData, Fs, nbits, readinfo] = wavread(fullWavFileName);
sound(waveFileData, Fs);
% soundsc(y,Fs,bits,range);
end
end
errorMessage = sprintf('Error in PlaySoundFile().\nThe error reported by MATLAB is:\n\n%s', ME.message);
fprintf('%s\n', errorMessage);
WarnUser(errorMessage);
end
return; % from PlaySoundFile
