WAVE file writing, confused about setsampwidth(n)

[Alex van der Spek]

I am confused about the Wave_write object setsampwidth(n).

Is the sample width n the total sample width, i.e. for a stereo sample 
consisting of short (2 byte) integers; n=4 or is the sample width the number 
of bytes in either the left or the right channel?

Regards,
Alex van der Spek