The source of the sound is the tripwire hook triggering, not the tripwire itself, thus the subtitle "Tripwire clicks" should be "Tripwire Hook clicks". This subtitle shows even when the only tripwire that is present is destroyed.

Steps to reproduce:

1. Setup a really long tripwire with hooks on either side (~12 blocks long)
2. Go on the far side and trigger the end
3. Notice the sound comes from the tripwire hook, not the actual tripwire