Error Codes & Troubleshooting

​

Authentication errors

​

WebSocket errors

​

Pronunciation dictionary errors

{
  "type": "error",
  "code": "pronunciation_not_found",
  "message": "Pronunciation dictionary not found: support-pronunciations"
}

​

Common issues

​

Connection drops

• Implement reconnection with exponential backoff (1s, 2s, 4s, up to 30s).
• Send periodic keep-alive messages ({"type": "keepalive"} for STT) to prevent idle timeouts.
• If behind a corporate proxy, confirm it supports WebSocket upgrades (the Connection: Upgrade header).

​

Choppy or distorted audio (TTS)

• Buffer at least 200ms of audio before starting playback.
• Use the WebAudio API (AudioContext) instead of <audio> elements for gapless chunk playback.
• Confirm your player’s sample rate matches the sample_rate from your init config.
• 24kHz linear16 audio requires roughly 384 kbps. Verify your connection can sustain it.

​

Delayed transcriptions (STT)

• Send audio in 20-100ms chunks (320-1600 bytes at 16kHz linear16).
• Confirm encoding and sample_rate in your init config match your actual audio format.
• For real-time use, prefer Deepgram Nova, which is optimized for streaming latency.

​

Audio format mismatch

{
  "encoding": "linear16",
  "sample_rate": 16000
}

​

Getting help

• Email: support@slng.ai
• Discord: discord.gg/slng