A Concise Introduction to Programming in Python

Chapter 20

Sound Synthesis

Now that we know how samples are used to represent sounds in a WAV file, we

can write programs to create our own sounds. In other words, we can create

synthesizers.

This program listing is not complete: you will need to add appropriate im-

ports, the writewav() function from Listing 19.1, and clampsample() from

Exercise 19.13.

Listing 20.1: Synthesizer

1 # synth.py

2

3 # imports and some function definitions deleted

4

5 def sinenote(step, sec, sampfreq):

6 data = array.array("h")

7 samples = int(sampfreq

*

sec)

8 freq = 440

*

2

**

(step / 12)

9 for i in range(samples):

10 y = 32767

*

sin(2.0

*

pi

*

freq

*

i / sampfreq)

11 data.append(clampsample(y, ...