hello
maybe this can be a starting point... just remembered I had this code around (zero crossing rate)
%% Read the input signal
[y, fs] = audioread('test_voice.wav');
N = length(y);
t = (0:N-1)/fs;
framelen = 128;
numframes = floor(N/framelen);
overlap = 0;
zcr = [];
for k = 1:numframes
frame = y((k-1)*framelen+1 : framelen*k) ;
arry = sign(frame(2:framelen)) - sign(frame(1:framelen-1));
zcr_frame = sum(abs(arry));
zcr = [zcr; zcr_frame] ;
end
% normalisation
zcr = zcr./max(zcr);
y = y./max(abs(y));
figure (1);
% t_zcr = (0:framelen:N-framelen)/fs ; % time stamp positionned at beginning of frame
t_zcr = (framelen/2:framelen:N-framelen/2)/fs ; % time stamp positionned at center of frame
plot(t,y,'b',t_zcr,zcr -1.5,'r');grid on;
xlabel('time(secs)'); ylabel('linear output')
