dreaming in sound?

Yesterday,Rhianna spent a delightful day with her favourite person (aside from mommy!),her mama Gee who is also her godmother.They went shopping (their favourite activity!)for sweets and candies for her coming birthday party.She wasn't very happy to go home but said her tearful goodbye anyway.
Later that night when she was asleep I spent the night wrapping her presents and preparing goodie bags for the party.Then I heard a small voice mumbling something..Thinking that she was awake,I went to check on her but she was fast asleep..suddenly she waved and said "bye bye mama Gee".
How sweet is that..she was probably dreaming about her outing.That left me wondering..Is she dreaming in sound?My deaf child is TALKING in her sleep..explain that!





Rhianna and mama Gee in one of their outings together