Original PCM boundary fixtures
These are conventionally synthesized hum examples, not recordings of a real room or model-generated audio.
Both files: mono, 16-bit PCM, 48000 Hz, 4 seconds.
Matched-endpoint example: 60 Hz and 240 Hz components; first and final samples set to zero.
Authored-step example: same interior waveform with a short deliberate ramp near the ending, creating a sample-value step at a wrap to the first sample.
The checker reports source samples without resampling. Matching endpoint values do not prove a seamless loop, a room match, loudness compliance or artistic suitability.
Listen to your real excerpt in context and inspect repetition, texture and perspective separately.