I couldn't find a good inhale sound in the Vocal Beatbox, so have created one from one of the MegaVoices. (If you've a Tyros, there is an MPad for it: Breathe)
These are the settings:
01:1:0000 Ctrl 0 8 MSB
01:1:0000 Ctrl 32 0 LSB
01:1:0000 Prog 65
01:1:0000 Ctrl 7 38 Vol
01:1:0000 Ctrl 91 16 Rev Send
01:1:0012 Note C#8 90 0002:0140
002:1:0000 End
You can also use C8 or D8