How to measure thock
Make a thock comparison you can repeat.
Put the iPhone in a consistent position, use the same key sequence, and record enough deliberate keystrokes for a stable session. Then compare the build before and after one change.
1. Fix the setup
Use the same room, surface, keyboard position, phone, and microphone orientation. Keep the phone about 20 cm from the keyboard when possible.
2. Repeat the test
Press the same keys with similar force. Avoid comparing a careful test with a rushed one or a quiet room with background noise.
3. Compare the evidence
Review thock, clack, decay, resonance, frequency balance, and consistency together. A single score is not a laboratory measurement.