It's an old question but one that is recurring thought for me.

Which would be most difficult to survive without vision or hearing.?

Assumption: You have been lucky enough to live to Adulthood with good vision and hearing.

I would have to choose hearing?
Why?
If you can see you have options:
Conversation - yes its possible to lipread or learn sign language.
Reading ... you can read books.
TV - there is often subtitles available

BUT the answer for me is ....
RADIO !

Yes I would give up seeing my photos again so I can hear and this is what its meant to me today.
My friends and families voices Spoke to my Mum an hour ago.
Music, yes ... Listened to Johnny Cash Unchained.
Radio Drama yes ... listened to The Archers
Radio Sports Commentary ( TMS, 5Live ) ... listened to Football
Podcasts Yes..... listening to Brexitcast NOW
Audio books Yes ... that's next

Radio Stations, BBC Radio 3,4,5,6 Classic FM, Scala