three-click.wav is generated mono 16-bit PCM at 22,050 Hz: three short identical 392 Hz clicks, 0.8 seconds apart. It contains no sampled recording, child voice, song or cultural rhythm. Play quietly only if a child wants an audible count; no device is required. Exact no-audio route: point to three large printed or raised numbered cards 1, 2, 3 at equal intervals; silent counting, sign or AAC is equally valid. No child is asked to copy a fast movement or record a response. Machine frame/onset checks are in the verifier; no human listening test has occurred.