Sound-command produces click-noise in a loop after each tone

Hello,

I am trying to make my impedance curve audible. My procedure (in Matlab):

• normalize data (Z/mean(Z))
• normalized data * sound frequence (440 Hz)
• determine the time per tone with e.g. 0.1 s (here I need a "time-array", because later I want to add the capacitance as the time => every tone another time (same for the duration). Now I want to add all these single tones to one "song" (background: I am working with impedance curves and have to explain my work to non-professionals - perhaps it will be easier with audible support =) )

Now my problem: after every single tone there is a "click"-noise, like turning old speakers on and off. I also tried to stick the sound vectors first together and play then the "sound-total" at one piece - does not work, too =/

Does anybody have an idea, why this click-noise is present? I would really appreciate that =) Furthermore, the sound is not around 440 Hz. Does anybody have a good working code for a sinusoidal sound?

I have spent so much time for this and I do not figure it out.

Thanks in advance. Regards,

elchico

My Code:

%%config settings 
    filename = 'Z_data.dat';    
    delimiter = '\t';               
    sound_freq = 440;               % in Hz, middle value to fluctuate around 
      fs = 20500;    % Sampling frequency 
      dt = 1/fs;     % time resolution 
      num_points = 10;    % How many points of raw data to convert into sound? 
      for jj = 1:num_points 
          duration(jj,1) = 0.1;                 % duration per note in sec 
          amplitude_array(jj,1) = 1;           % a.u., middle value to fluctuate around (=> volume)   
      end 
%%calculate values (Z_norm) and refer to sound 
    M_raw = dlmread(filename,delimiter); 
    Z_values = M_raw(1:num_points,1); 
    Z_norm= Z_values /mean(Z_values ); 
      sounds_freq_array = Z_norm*sound_freq,0; 
%%play sound 
   for ii= 1:num_points                 
        t = 0:dt:(duration(ii,1)); 
          signal = amplitude_array(ii,1)*sin(2*pi*sounds_freq_array(ii,1)*t); 
          sound(signal, (fs)); 
          pause (duration(ii,1)); 
     end

And here are some example-data:

8406
8200
8000
8500
8365
8400
7999
8555
8336
8456

Answer 1

[elchico]

Noone with an idea? I would really appreciate it. Regards