please explain this code

gen_det.m [file_name file_path] = uigetfile ({'*.wav'}); if file_path ~= 0 filename = [file_path,file_name]; end [y, fs]=audioread(filename); wavplay(y,16000); cla; %axes(handles.axes1); time = length(y)/fs; if time == 0 %the first, second and third lines of the message box msgboxText{1} = 'You have tried to estimate gender without recording signal'; msgboxText{2} = 'Try recording a signal using record button'; %this command actually creates the message box msgbox(msgboxText,'Signal recording not done', 'warn'); else ms20 = fs/50; t = (0:length(y)-1)/fs; gen_det_sph(time,ms20,fs,y) figure; plot(t,y); title('Waveform'); xlabel('Time (s)'); ylabel('Amplitude'); wavplay.m function wavplay(signal, sampleRate) % WAVPLAY Plays an audio signal using the audioplayer object. % WAVPLAY(x, Fs) plays the audio signal x at the specified sample rate Fs. % Instantiate object to play audio data. player = audioplayer(signal, sampleRate);

 % Play signal from beginning to end (no overlap with other code 
possible).
 playblocking(player);
end
gen_det_sph.m
function gen_det_sph(time,ms20,fs,x)
cla;
if time == 0
 %the first, second and third lines of the message box
 msgboxText{1} = 'You have tried to estimate gender without recording 
signal';
 msgboxText{2} = 'Try recording a signal using record button';
 %this command actually creates the message box
 msgbox(msgboxText,'Signal recording not done', 'warn');
else
 %calculate autocorrelation
 r = xcorr(x, ms20, 'coeff');
 %plot autocorrelation
 d = (-ms20:ms20)/fs;
 plot(d, r);
 title('Autocorrelation');
 xlabel('Delay (s)');
 ylabel('Correlation coeff.');
 ms2 = fs/500; %maximum speech Fx at 500Hz
 ms20 = fs/50; %maximum speech Fx at 50Hz
 %just look at region corresponding to positive delays
 r = r(ms20 + 1 : 2*ms20+1);
 [rmax, tx] = max(r(ms2:ms20));
 Fx = fs/(ms2+tx-1);
end 
 if Fx <= 175 && Fx >=80
 msgboxText{1} = ('Male');
 msgboxText{2} = num2str(round(Fx));
 msgbox(msgboxText,'Signal detection done', 'warn');
 elseif Fx>175 && Fx<=255
 msgboxText{1} = ('Female');
 msgboxText{2} = num2str(round(Fx));
 msgbox(msgboxText,'Signal detection done', 'warn'); 
 else
 msgboxText{1} = ('Sorry not recogansed');
 msgboxText{2} = num2str(round(Fx));
 msgbox(msgboxText,'Signal recording not done', 'warn'); 
 end
end

Answer 1

[Hari]

Hi Vineeth,

The code involves functions and scripts to read, play, and analyze a .wav audio file to determine the gender based on the fundamental frequency (Fx).

I assume that the audio file you are working with contains a clear speech signal for accurate gender detection.

Here is the explanation for the important sections of the code:

File Selection and Audio Reading:

The code uses uigetfile to prompt the user to select a .wav file. If a file is selected, audioread reads the audio data and sample rate.

[file_name, file_path] = uigetfile({'*.wav'});
[y, fs] = audioread(filename);

Playing the Audio:

The wavplay function is defined to play the audio using the "audioplayer" object. It plays the signal at the specified sample rate.

player = audioplayer(signal, sampleRate);
playblocking(player);

Gender Detection Logic:

The gen_det_sph function calculates the autocorrelation of the audio signal and uses it to estimate the fundamental frequency (Fx). Based on Fx, it categorizes the signal as male or female.

r = xcorr(x, ms20, 'coeff');
[rmax, tx] = max(r(ms2:ms20));
Fx = fs/(ms2+tx-1);

Result Display:

The code uses msgbox to display the detected gender or any issues (e.g., no signal recorded). The frequency is rounded and shown in the message box.

if Fx <= 175 && Fx >= 80
    msgboxText{1} = 'Male';
elseif Fx > 175 && Fx <= 255
    msgboxText{1} = 'Female';
else
    msgboxText{1} = 'Sorry not recognized';

Plotting:

The waveform of the audio signal and its autocorrelation are plotted using plot, providing a visual representation of the signal and its analysis.

    plot(t, y);
    plot(d, r);

Refer to the documentation of "uigetfile": https://www.mathworks.com/help/matlab/ref/uigetfile.html

Refer to the documentation of "audioread": https://www.mathworks.com/help/matlab/ref/audioread.html

Refer to the documentation of "audioplayer": https://www.mathworks.com/help/matlab/ref/audioplayer.html

Refer to the documentation of "xcorr": https://www.mathworks.com/help/signal/ref/xcorr.html

Hope this helps!