Understanding the ALSA configuration
Like so many things in the Linux, Debian, and Raspbian environments, the configuration of the sound capabilities is contained in files maintained by the OS. For ALSA, the configuration files are in the /proc/asound directory and can be viewed using File Manager or from the command prompt, as shown in the following screenshot:
In ALSA, the interfaces are associated with the concept of a card and, in larger computers, the audio adapter may be a physical card plugged into a backplane. In the command prompt view shown in the preceding screenshot, there are two cards shown. One is the internal bcm2825 (the chip number for the SOC in the Pi models prior to the 2-B) and the other is the Microsoft Webcam we attached to our system that has a microphone for audio capture.
There are several ALSA utilities that can be started at the command-line prompt:
alsamixer: This utility provides controls for volume and can list card and device informationaplay: This utility...
