You might try testing the individual sound files to be sure they sound OK when played alone. Trying a Wait(1) between each sound file might also provide a clue as to what’s wrong.
also, look in /var/lib/asterisk/sounds/digits (or whatever the equivilant on BSD is) to see if you have all the digits in the same formats… especially in the native format of the call.
I need the “call parking” function… Then I dial *4, Asterisk is trying to play 1201 (as I see on the log), but I hear leading “one” and, sometimes, trailing “one”