Check by looping back microphone to speaker

The easiest way to check if both microphone and speaker are functioning properly is by using pjsua and looping the microphone to the speaker in the conference bridge:

run pjsua, e.g:
- for desktop, pjsua sample app is automatically built, so simply run it from console:
  $ ./pjsua
- for mobile platforms, pjsua CLI sample app usually needs to be built manually (check Get Started wiki of the platform, e.g: Android, or iPhone/iOS, run it on the device and start a telnet session to pjsua CLI app running on the device from desktop console, e.g:
  $ telnet 192.168.1.101 2323
  Wait until telnet session is established. Check PJSUA Command Line Interface (CLI) Manual for more info about pjsua CLI.
loopback microphone to the speaker:
```
>>> cc 0 0
```

Now whatever captured in your microphone will be played-back locally to your speaker.

Note

This step is not recommended for PDA application since on PDA, the echo suppressor will cut the microphone signal once it detects that something is playing in the speaker.