Change Sample Rate Audio

Here's Matlab Audioread I try:

filename = "test.wav";
[y,fs] = audioread(filename);
%Play the audio.
sound(y,fs);
info = audioinfo("test.wav")

And here is the info from that audio:

CompressionMethod: 'Uncompressed'

NumChannels: 2

SampleRate: 44100

TotalSamples: 487424

Duration: 11.0527

Title: []

Comment: []

Artist: []

BitsPerSample: 16

My question is, How do I play the audio at a sample rate of 8000?

Answer 1

[Star Strider]

I would do something like this, using the Signal Processing Toolbox resample funciton —

filename = "test.wav";

[y,fs] = audioread(filename);

L = size(y,1);

t = linspace(0, L-1, L)/fs; % Time Vector

fs_new = 8000;

[yr,tr] = resample(y, t(:), fs_new); % Resample To New Sampling Frequency

There are several compatible resample syntaxes that will do what you want. I prefer the one I posted here.

Alternatively, the interp1 funciton can be uesd, however resample includes an anti-aliasing filter, so it is best for any sort of signal processing.

.

[Ibnu Darajat]

when I want to play the audio with this code:

sound(yr,tr)

there is error I got:

Error using sound (line 76)

Operands to the || and && operators must be convertible to logical scalar values.

Error in openaudio>pushbutton1_Callback (line 89)

sound(yr,tr)

Error in gui_mainfcn (line 95)

feval(varargin{:});

Error in openaudio (line 42)

gui_mainfcn(gui_State, varargin{:});

Error in

matlab.graphics.internal.figfile.FigFile/read>@(hObject,eventdata)openaudio('pushbutton1_Callback',hObject,eventdata,guidata(hObject))

Error while evaluating UIControl Callback.

>>

[Star Strider]

Try this instead:

sound(yr,fs_new)

That should work correctly.

Use ‘tr’ to plot it:

figure

plot(tr, yr)

grid

xlabel('Time (s)')

ylabel('Amplitude')

.

[Ibnu Darajat]

there is 2 color when I plot the signal? What's the different?

[Star Strider]

It is not necessary to plot it. I simply wanted to show how to use the ‘tr’ vector correctly. (There should be some differences between the original and resampled vectors because of the interpolation being used.)

To listen to the resampled version, do this —

sound(yr,fs_new)

or use the audioplayer and play functions. (The sound function is easier.)

.

[Ibnu Darajat]

thanks

[Star Strider]

As always, my pleasure!