Concatenation two arrays means chaining them together. for sound, this means putting signals together to hear them one at a time. in matlab, two vectors can be concatenated through the notation:
zz = [xx, yy];
run a script or function for each example for your lab doc.
1. run soundsc() on an input signal/sinusoid. using = 11025 , instantiate a time vector of 0.5 second duration. create a vector x1 of samples of a sinusoid with amplitude = 100, angular frequency = ), and phase phi = − 3 . play the vector and listen to the output. note: if soundsc() does not work for you, in this case use audiowrite() (run audiowrite) to create a .wav file. the .wav file can be played by most media players.
2. run soundsc() on a second input signal/sinusoid: create a vector x2 of samples of a sinusoid with = 80, = ), and phi = 4 . use = 11025 and obtain a number of samples equivalent to a 0.8 second duration. play the vector and listen to the output.
3. concatenate the input signals together: concatenate x1 and x2 into a vector x, leaving a duration of 0.1 seconds of silence in between.
hint: use
listen to this new signal to verify that it is correct.
4. plot and identify the two input signals. execute the following commands, and plot: > > tt = (1/11025)*(1: length(xx)); > > plot(tt, xx); this will plot a huge number of points, but you should be able to discern the "envelope" of the signal. verify that the amplitude changes from 100 to 0, and then from 0 to 100 at the correct times.
5. different sampling frequencies affecting pitch: call soundsc() on x again (or use audiowrite() and play the output file), but this time use = 22050 .
describe how the duration and pitch of the signal were affected and explain.
6. using the t vector from section 2.1.4 of this lab, create sounds for the following frequencies:
[523, 587, 659, 698, 784, 880, 988, 1047]
concatenate the sounds together, and *submit the concatenated sound (a musical scale) as a single .wav file using audiowrite. remember to include code and .wav file.
question 11: how does this sound compare to the output of the previous sound?