find the dominant frequency with the use of the command max

I have a file named “message.txt” containing the waveform of a voice message embedded in a sinusoid with frequency of 220 Hz, and the sampling frequency is 22000 Hz.

file source: http://www.2shared.com/document/LCmLelLW/message.html

load the file, and the speech heard

 load message.txt
 soundsc(message, 22000)

the spectrum of message,where the magnitude plot of the Fourier transform for message versus frequency in Hz, is observed using the following code

 [freq_resp,freq_index]=freqz(message,1,100000,22000);
 plot(freq_index,abs(freq_resp))

how can i find the dominant frequency of message with the use of the command max?

i tried

 C = max(freq_index)

it does not work

Answer 1

[Sachin Ganjare]

Refer the link below:

http://www.mathworks.com/matlabcentral/newsreader/view_thread/319394

Hope it helps!!!!

[Passband Modulation]

it does really help... anyway thx for ur kind reply