Making an air drum

To create a drum, we need to have sound. It is a new topic. Chapter 7, Audio Programming, will have a more detailed introduction to audio in Pure Data. In this example, we use a very basic feature of playing a sound file interactively. Before we start, we have to collect a few sound samples. We use a few free audio clips from the public domain, such as http://freesound.org. They will produce the sound of a kick drum, snare drum, and tom-tom. We also need to take a look at the sampling rate of the sound files. Analog sound is converted into discrete samples during digitization. Sampling rate is the number of sample units in a second. Ours is 44 kHz, which is a common standard. The sampling rate has to match the preference settings in Pure Data, otherwise they may be distorted. You can use the Get Info or Properties options to check the audio file information:

For the Pure Data audio information, go to Preferences | Audio Settings...:

Within the Audio Settings... option, you...