The bug

Detector rails do not make any sounds when a minecart rolls over them. This is unlike many other redstone input devices, which have a distinct clicking sound for when tiggled in a similar manner to detector rails.

How to reproduce

1. Place down a pressure plate, or set up tripwire in a valid circuit
2. Trigger the pressure plate and/or tripwire
   1. Note the trigger sound that plays as a result
3. Now trigger a detector rail in a setup for it
   1. Note the distinct lack of trigger audio

Expected results

Like other redstone switch components, triggering a detector rail would result in some sort of clicking sound to indicate it had been triggered.

Actual result

Detector rails are completely silent, unlike other related redstone switches.