When the line-out speaker is selected as the sound output, the sound
is fine. Sound comes only from the speakers connected to the line-out port. However, when the headphone is selected as the output device,
sound comes out both from the headphone and the speakers.
My desktop computer has three sound output options:
- HDMI/Display port (not used)
- Headphone port at the front (headphone
- Line-out port at the back (speakers connected)
When line-out is selected as the output device, the sound is
heard only from the speakers connected to the line-out port. No problem there.
However, when headphone is selected as the output device, the sound is
heard both from headphones and the speakers connected to the line out
This is really strange and beats the very purpose of the headphone,
namely, privacy and not disturbing others.
My sound card as found is as follows.
sudo aplay -l
**** List of PLAYBACK Hardware Devices **** card 0: PCH [HDA Intel PCH], device 0: ALC3234 Analog [ALC3234 Analog]
I even tried setting the sound volume of the line-out to zero in
settings. This works for the line-out speakers. However, this does not
seem to have any effect on the sound volume when the headphone is
selected. The line-out speakers are equally loud, even with the sound volume set to zero.
I am not sure whether the output from
alsamixer will be useful. But
here it goes anyway.