This workaround has been tested and worked in Ubuntu 22.04, and should be working too for Ubuntu 20.04, 18.04, and a few earlier.
No microphone input on Acer Aspire One and Lenovo Ideapad 310-15ISK/330-15ARR
Install pavucontrol, unlink the microphone channels and turn down the left one to 0.
- apt install pavucontrol
run pavucontrol (pulse audio volume control) from terminal or applications
Some applications (e.g. chromium) can change microphone levels causing the same issue, a workaround is to remap stereo input to mono and use the remapped device as default.
Another Possible Cause
Another possible cause is that your mic has two channels but only one channel can provide a valid sound signal. Some information can be found here. The solution is to remap the stereo input to a mono input:
1. Find your source name from the following command; mine is alsa_input.pci-0000_00_1f.3.analog-stereo
pacmd list-sources | grep 'name:.*input'
2. Edit /etc/pulse/default.pa and add the following lines, where INPUT_NAME is name of the input source from above step:
load-module module-remap-source source_name=record_mono master=INPUT_NAME master_channel_map=front-left channel_map=mono set-default-source record_mono
3. Restart PulseAudio:
$ pulseaudio -k $ pulseaudio --start
Now arecord hopefully works. You may still need to change the RecordStream from setting to Remapped Built-in Audio Analog Stereo of a specific application in the Recording tab of pavucontrol.
Source :
Muhammad Bintang's Weblog 