class MyClient(discord.Client):
...
async def on_voice_state_update(self, member, before, after):
if after.channel and after.channel!=before.channel:
print(f"Пользователь {member.name} зашол на {after.channel.name}")
if before.channel and after.channel!=before.channel:
print(f"Пользователь {member.name} вышел с {before.channel.name}")