internal speakers

suddenly i can't hear any sound from my internal speakers in my macbook air. I can't find internal speakers in my audio settings when i go to system preference. there is an audio sign with a slant stroke \ across it at the menu bar. my vlc plays video but no audio, apple music has no audio, no start up audio when i power on.

i can however still play audio with an external speaker

my ios, vlc are all up to date. have tried restarting, yet still no audio from build in speakers

any help pls