Comment 95 for bug 1201528

you mplayer did not require low latency playback

Jul 24 09:20:47 dali pulseaudio[2800]: [pulseaudio] protocol-native.c: Requested tlength=250.00 ms, minreq=20.00 ms
Jul 24 09:20:47 dali pulseaudio[2800]: [pulseaudio] protocol-native.c: Traditional mode enabled, modifying sink usec only for compat with minreq.
Jul 24 09:20:47 dali pulseaudio[2800]: [alsa-sink-ALC889 Analog] alsa-sink.c: Expected sleep: 160.98ms, real sleep: 0.22ms (diff -160.76 ms)

but mumble require low latency playback

1383327649.384264-1444531632"
( 7.432| 0.000) I: [pulseaudio] sink-input.c: module-stream-restore.id = "sink-input-by-media-role:phone"
( 7.433| 0.000) I: [pulseaudio] protocol-native.c: Requested tlength=60.00 ms, minreq=10.00 ms
( 7.433| 0.000) D: [pulseaudio] protocol-native.c: Adjust latency mode enabled, configuring sink latency to half of overall latency.

do you know whether mumble receive enough voice audio from the internet voice chat ?

under run can occur if your sound card playback faster than your partner 's sound card capture

or

buffer overflow when your sound card playback slower than your partner's sound card capture