My speakers went down today and I can't find my earphones, so I played for several hours without sound. I had to use subtitles. One of the advantages was not having to hear the continuous blabbing of that alchemist in Whiterun and the inane blather of shopkeepers. Boy, that woman gets on my nerves. A disadvantage is not knowing you're being attacked from behind until you see blood spots on your lens. You get used to no sound after a while, but you miss the music and sound effects. I must go out tomorrow and get new speakers.
I'd be interested to hear if anyone else plays or has played with the sound off.

I usually only get a 'What do you need, my friend ?' from her after the frost salts quest

Sound wise, I likes me some music and background noises, and use one of the NPC reduced distance greeting mods to cut down on the nattering,

I play everyday without the sound on I mostly listen to the radio while I'm playing but when I don't have the radio on I do have the volume up.