There are 11 pins, #0 thru #10, the sound board looks at each pin, in order starting with #0 and if it sees that pin connected to ground checks if it can find a Tnn file to play | There are 11 pins, #0 thru #10, the sound board looks at each pin, in order starting with #0 and if it sees that pin connected to ground checks if it can find a Tnn file to play |