In the air drum exercise of Chapter 5, Motion Detection, we learned how to playback an external sound file. The Audio001.pd patch shown in the following screenshot shows how we can do so:
Remember that all audio-related objects come with the ~ character suffix. The object readsf~ reads an external sound file through the open message. The message 1 starts the playback. The message 0 stops it. Its left-hand outlet is the audio signal going to the digital-to-analog converter, the dac~ object. The dac~ object will actually play the audio signal through the computer's audio interface. The right-hand outlet of readsf~ is a bang message that will be triggered once the playback reaches the end of the sound file. Note that the line connecting audio outlet and inlet is thicker than normal data connection.
If you click on the Play button a few times before the first sound file ends, the patch will initiate a new playback every time you click. It may cause trouble in your design...