Comment by rzzzt

This can be resolved by sampling a real hard drive's sounds (spin-up, idle, spin-down, short seek, long seek, big klonk etc.) and playing it back in plausible sequences and variations. You might have to add some mixing capability as well since the motor will drone on constantly.

On the ultra realistic end: take a dead hard drive, trim the head assembly back so it won't touch/scratch the platter surface, remove its original PCB and replace it with the simulator which now will be responsible for driving the motor and the voice coil. If there is some space left for SSD storage, slap that on as well and use the original power and data connections.