{
  "event_id": "evt_transcript_failed_001",
  "type": "conversation.item.input_audio_transcription.failed",
  "item_id": "item_audio_001",
  "content_index": 0,
  "error": {
    "type": "transcription_error",
    "code": "audio_unintelligible",
    "message": "The audio could not be transcribed."
  }
}