I want use function tfrsp of my sound from microphone

Hello. I have problem with function tfrsp. I want to use that function for spectrogram of sound. I can get the spectrogram of regular signal. This is the only thing what I can get from help tfrsp

 tfrsp  Spectrogram time-frequency distribution.
   [TFR,T,F]=tfrsp(X,T,N,H,TRACE) computes the Spectrogram 
   distribution of a discrete-time signal X. 

   X     : signal.
   T     : time instant(s)          (default : 1:length(X)).
   N     : number of frequency bins (default : length(X)).
   H     : analysis window, H being normalized so as to
           be  of unit energy.      (default : Hamming(N/4)). 
   TRACE : if nonzero, the progression of the algorithm is shown
                                    (default : 0).
   TFR   : time-frequency representation. When called without 
           output arguments, tfrsp runs TFRQVIEW.
   F     : vector of normalized frequencies.

   Example :
    sig=fmlin(128,0.1,0.4);
    h=tftb_window(17,'Kaiser'); tfrsp(sig,1:128,64,h,1);

         [tfr,t,freq]=tfrsp(sig,1:128,64,h,1); plot(fftshift(freq),fftshift(tfr(:,100)))

When I try to use some sound what I took from my microphone example:

sig=audiorecorder;

record(sig);

stop(sig);

play(sig);

h=tftb_window(17,'rect');

[tfr,t,f]=tfrsp(sig,1:128,64,h,1);

Spectrogram

Undefined function 'times' for input arguments of type 'audiorecorder'.

Error in tfrsp (line 87)

 tfr(indices,icol)=x(ti+tau).*conj(h(Lh+1+tau))/norm(h(Lh+1+tau));

>>or if I change time [tfr,t,f]=tfrsp(sig,1:length(sig),64,h,1);

Spectrogram

100 % complete in 0 seconds.

Undefined function 'times' for input arguments of type 'audiorecorder'.

Error in tfrsp (line 87)

 tfr(indices,icol)=x(ti+tau).*conj(h(Lh+1+tau))/norm(h(Lh+1+tau));

thanks in advance.

Answer 1

[Star Strider]

I am not certain what you are doing, but if you want to get your recorded sound as numeric array, you have to use the getaudiodata function.

This works:

Fs        = 1E+4;
nBits     =   24;
nChannels =    2;
sig = audiorecorder(Fs, nBits, nChannels);
recordblocking(sig,5);
sigsound = getaudiodata(sig);

t = linspace(0, size(sigsound,1), size(sigsound,1))/Fs;
figure(1)
plot(t, sigsound)
grid
xlabel('Time (s)')
ylabel('Amplitude (kPa)')

It plots the amplitude as a function of time, not the spectrogram, but it illustrates the idea.

I cannot find any information on ‘tfrsp’. It is not in the online documentation, and I cannot find it in the File Exchange, so I cannot help you with it. (I have the Signal Processing Toolbox, that has the spectrogram function.)

Also, be certain that your microphone is turned on! In Windows machines, go to Control Panel > Sound to be sure.

[matija corak]

Thanks

[Star Strider]

My pleasure!