How sound can hang ...

I finally found it! I've been plagued with random gnome app hangs (usually gnome-panel, but plenty of other apps as well). I started stracing some of the hanging apps and it wouldn't give me much, but if I killed them, and restarted them under strace, I'd always see something like this at the end:

access("/tmp/.esd-501/socket", R_OK|W_OK) = 0
socket(PF_FILE, SOCK_STREAM, 0) = 18
fcntl64(18, F_SETFD, FD_CLOEXEC) = 0
setsockopt(18, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
connect(18, {sa_family=AF_FILE, path="/tmp/.esd-501/socket"}, 22) = 0
rt_sigaction(SIGPIPE, {0x3d07c0, [PIPE], SA_RESTART}, {SIG_IGN}, 8) = 0
open("/home/foo/.esd_auth", O_RDONLY) = 19
read(19, "\371\27PG\6\f2utX=!\f\2):", 16) = 16
write(18, "\371\27PG\6\f2utX=!\f\2):", 16) = 16
write(18, "NDNE", 4) = 4
read(18,

It was always hanging trying to read this esd socket. After seeing several of these, I searched online, and it took me almost no time to find this once I searched on 'gnome-panel hangs esd socket'. This has been bugging me for weeks, and I had blamed it all on Notes 8. Nice to know I was wrong.

Looks like killing esd, pulseaudio or both resolves this problem. Previously I was actually having to reboot to resolve this!