[maxmsp] (off topic) Apple F Major

Hello

How do you completely remove this F major chord that rings every time a Mac boots up ?

To make things clear:
- all volumes are set to "zero", "silence", and/or "mute"
- headphones are plugged into the output of the inboard sound card
- when rebooting, the chord is still here (in the speakers of the laptop) !


Thanks for your help ...