Confirmed: High-frequency whistle (sounds like exceeding Nyquist frequency) with ALC882+pulseaudio when playing any audio in 5.1 analog output.
Fix works: ; default-sample-format = s16le default-sample-format = s24le $ pulseaudio -k Then, whistles gone. Sound driver: hda_snd_intel. On-board sound: Asus P5W DH Deluxe with (ALC882) audio Kernel: Linux somer 2.6.31-17-generic #54-Ubuntu SMP Thu Dec 10 17:01:44 UTC 2009 x86_64 GNU/Linux $ lspci -vnn 00:1b.0 Audio device [0403]: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller [8086:27d8] (rev 01) Subsystem: ASUSTeK Computer Inc. Device [1043:81d8] Flags: bus master, fast devsel, latency 0, IRQ 19 Memory at febfc000 (64-bit, non-prefetchable) [size=16K] Capabilities: [50] Power Management version 2 Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable- Capabilities: [70] Express Root Complex Integrated Endpoint, MSI 00 Capabilities: [100] Virtual Channel <?> Capabilities: [130] Root Complex Link <?> Kernel driver in use: HDA Intel Kernel modules: snd-hda-intel Two notable things also occured that might be useful in diagnosing: 1. Was getting a bunch of rate limit messages before default-sample- format changed to s24le. Afterward, the rate-limit messages were reduced considerably even after I went back to s16le. You can see that in messages log. Comments in square brackets. Dec 16 23:07:19 somer pulseaudio[2260]: ratelimit.c: 177 events suppressed Dec 16 23:18:07 somer pulseaudio[2260]: ratelimit.c: 180 events suppressed Dec 16 23:20:58 somer pulseaudio[2260]: ratelimit.c: 179 events suppressed Dec 17 00:02:41 somer pulseaudio[2260]: ratelimit.c: 176 events suppressed Dec 17 00:20:10 somer pulseaudio[2260]: ratelimit.c: 172 events suppressed Dec 17 00:20:41 somer pulseaudio[2260]: ratelimit.c: 43 events suppressed [daemon.conf changed and PA killed] Dec 17 00:22:04 somer pulseaudio[21491]: alsa-mixer.c: Your kernel driver is broken: it reports a volume range from 18.00 dB to 18.00 dB which makes no sense. Dec 17 00:23:33 somer pulseaudio[21491]: last message repeated 6 times Dec 17 00:25:09 somer pulseaudio[21491]: ratelimit.c: 5 events suppressed Dec 17 00:27:49 somer pulseaudio[21491]: ratelimit.c: 2 events suppressed [continues with approx. 1 - 10 events per report] 2. Everytime PA is killed this appears in messages and syslog: Dec 17 00:34:00 somer pulseaudio[22677]: alsa-mixer.c: Your kernel driver is broken: it reports a volume range from 18.00 dB to 18.00 dB which makes no sense. 3. Twice received this message in syslog: Dec 17 00:25:03 sophia pulseaudio[21491]: alsa-sink.c: ALSA woke us up to write new data to the device, but there was actually nothing to write! Dec 17 00:25:03 sophia pulseaudio[21491]: alsa-sink.c: Most likely this is a bug in the ALSA driver 'snd_hda_intel'. Please report this issue to the ALSA developers. Dec 17 00:25:03 sophia pulseaudio[21491]: alsa-sink.c: We were woken up with POLLOUT set -- however a subsequent snd_pcm_avail() returned 0 or another value < min_avail. ** Changed in: pulseaudio (Ubuntu) Status: New => Confirmed -- after upgrade to karmic during audio playback a high-frequency whistling can be heard https://bugs.launchpad.net/bugs/475997 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs