i can relate... my 4-month old Venus is deaf as well.. she was born deaf.
The day i picked her up, driving en route home, i cried ... i guess i was feeling so bad for her, that she could not enjoy the jazz music that was on, etc... my heart was really painful that day...
At home, she is a rowdy one... a lot of times, when she catches Daisy (my other kitty) sleeping in her bed, she puts on her aggressive shoes, and starts attacking and "fighting" her till Daisy gets out of the bed!!:tounge2:
Also, many times, she plays with the furry toys in a very rough and aggressive manner.. i have to stand back and make room for her!!
Maybe they are just venting ... my Venus hardly speaks, and even when she opens her little mouth, she makes the softest noises... so, i just let her be, and let her vent and vent...
Just give your Kahu some toys to play with, it helps with my Venus... also, i play with her alot.. just clowning around throwing her favorite toys in the air and such.. she always enjoys catching them as they land... also, those interactive toys like snakes and feathers work well with her.