{"id": "u001", "audio": "digits-0123-clean.wav", "text": "zero one two three", "duration_ms": 900}
{"id": "u002", "audio": "digits-4567-clean.wav", "text": "four five six seven", "duration_ms": 900}
{"id": "u003", "audio": "digits-89-clean.wav", "text": "eight nine", "duration_ms": 500}
{"id": "u004", "audio": "pin-1357-clean.wav", "text": "one three five seven", "duration_ms": 900}
{"id": "u005", "audio": "seq-24680-clean.wav", "text": "two four six eight zero", "duration_ms": 1100}
{"id": "u006", "audio": "seq-987654-clean.wav", "text": "nine eight seven six five four", "duration_ms": 1300}
{"id": "u007", "audio": "yes-1-clean.wav", "text": "one", "duration_ms": 300}
{"id": "u008", "audio": "no-0-clean.wav", "text": "zero", "duration_ms": 300}