reduce audio quality in mpv

I have very limited data in a remote area and so I listen to youtube (and other video platforms) using

--no-video

. Does anyone know how to lower the audio quality so that I can reduce my streaming data usage even more? (most of what i listen to is just talk). I tried adding

=fast

in

.conf

but mpv didn't recognize it. I also searched through

mpv

but couldn't find what I wanted. I am using Linux Mint 21.2 UPDATE: Using the accepted answer and searching

mpv | grep ytdl

, I ended up with:

--no-video --ytdl-format=worstaudio/worst

This reduced data usage by almost half and as far as a podcast goes, there is little difference in listen-ablity.