If needed, before displaying the sound generated from the mixed tracks, you can:
click to mute a track, that is to say
temporary exclude it from the mix,
double-click the dB field of a track to adjust its
gain.
Click located on the upper right corner of the Sound
Composer Window.
The waveform of the sound generated from the mixed tracks opens in
a new window. You can now play it using the Playback controls, calculate its spectrogram or
psychoacoustics indicators.