I am playing short sound effects using
aplay whenever users interact with the interface.
What I notice is that I can play any of the sounds in any order and as long as two sounds play within 5 seconds of each other the transition is clear, but a gap of anymore than 5 seconds and there is a horrible pop!
Note that all of my sound files are < 1 second in duration.
What I have done to hack around this is to create a 5 second long low sample rate silence.wav file that loops in an .sh script (which is definitely not a long term solution):
Brute forcing with silence:
#!/bin/bash while [ 1 ] ; do aplay sounds/blank.wav done
The popping is now very seldom, if at all.
So what I can't figure out is why the heck something is changing in those 5 seconds to cause the pop? How can I configure my audio to remain in a state where it won't pop when a sound is played after a long delay?
I have experimented with /etc/pulse/default.pa and /etc/pulse/daemon.config but have made zero progress.
Note that I am using a single core raspberry pi, but if brute forcing with silence helps, then there's still hope??
I came across a slightly more elegant way to continuously brute force silence to the devices:
aplay /dev/zero Playing raw data '/dev/zero' : Unsigned 8 bit, Rate 8000 Hz, Mono
But for some reason it produces a high frequency tone instead. Is there possibly a similar way to do this?
aplay -r 8000 -f S16_LE /dev/zero
This does the trick, with some overhead of running a thread constantly to keep things open. But otherwise very clean audio now.
This feature is related to the pulseaudio module module-suspend-on-idle. Also possible to disable this module. Try temporary first:
pactl unload-module module-suspend-on-idle
If you are satisfied, then you can make this setting temporary in the pulseaudio configuration file.