As speaker you can operate LiveVoice not only with the mouse but also with your keyboard.

Here are the hot keys for it:

Basics: 

• Start: s
• Stop: p
• Mute: m or space

Play: 

• Channel 1: 1
• Channel 2: 2
• Channel 3: 3
• ... 

Channel Switch:

• A: a
• B: b
• C: c
• D: d

Handover: 

• Take over: s
• Hand over: h
• Accept: s
• Decline: n
• Cancel: n