Disappearing Trim Noise

I love the noise that the elevator trim makes while it is adjusting. I find that when I load the default flight, most times the trim sound is not there. If I reselect the same aircraft or any other PMDG 737 , it comes back as soon as the aircraft loads. Once I get it back I save the flight, make that flight the new default, and most times when recalling it the sound is gone again. This sometimes happens with the fire alram bell also. Anyone else noticing this and or found a solution?