Headphone jack on 17.10

my headphone which i connected to my laptop via the headphone jack was not detected, i opened a video on youtube and the audio came from the laptops speakers. any help on this is appreciated.

Linux has a bit of a problem, in my experience, automatically detecting a change of sound devices on the fly.

There are two ways of dealing with this.

The first is to click the volume icon and choose “settings” and then the output tab and choose the device you wish the sound to come out of.

The second is to install indicator-sound-switcher. This is an applet the sits on your panel in the notifications area and allows you to quickly pick the output device from a drop down list.

I always use the second method.

See video below:

This is the version I currently use:

https://launchpad.net/~yktooo/+archive/ubuntu/ppa/+files/indicator-sound-switcher_1.2.2ubuntu0-gtk3ppa0-1_all.deb