Noise cancellation removes background audio before Rapida runs Voice Activity Detection and Speech-to-Text. It helps prevent false speech detection and improves transcription quality when users speak from phones, shared offices, vehicles, cafes, or other noisy environments.Documentation Index
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Noise cancellation is configured in Voice Input under Show advanced settings. It is part of the deployment voice configuration, so each deployment can use its own setting.
Provider
Rapida exposes RNNoise as the standard noise cancellation provider. RNNoise is designed for real-time speech enhancement. It reduces steady background noise while preserving speech intelligibility, making it a good default for phone calls and browser microphone sessions.| Provider | Best for | Notes |
|---|---|---|
| RNNoise | Phone calls, office noise, keyboard noise, light traffic, cafes | Default choice for most voice deployments. |
When to use it
Enable noise cancellation when:- Calls happen over PSTN or mobile networks.
- Users may be in offices, stores, vehicles, cafes, or shared spaces.
- VAD triggers on background audio.
- STT receives noisy audio and produces unstable transcripts.
- You want one safer default across many caller environments.
- Audio is already clean studio-quality input.
- Another upstream system already performs strong noise suppression.
- You hear speech artifacts after enabling it.
- The STT provider performs better with untouched audio in your test calls.
How it affects the pipeline
| Component | Effect |
|---|---|
| VAD | Cleaner audio reduces false speech starts from background noise. |
| STT | Cleaner speech can improve transcript stability and word accuracy. |
| EOS | Better VAD activity signals make turn detection more predictable. |
| TTS | No direct effect. TTS happens after the assistant generates text. |
Tuning with VAD
Noise cancellation and VAD should be tuned together.| Symptom | What to adjust |
|---|---|
| Background noise interrupts assistant speech | Keep RNNoise enabled and raise VAD threshold. |
| Quiet speakers are missed | Keep RNNoise enabled, then lower VAD threshold slightly. |
| Words are clipped at the start | Lower VAD threshold or reduce minimum speech frames. |
| Speech gets split into multiple chunks | Increase VAD minimum silence frames. |
Channel guidance
| Channel | Recommendation |
|---|---|
| Phone Call | Enable RNNoise by default. Phone audio is often compressed, narrowband, and noisy. |
| Web Widget | Enable RNNoise when users may speak from uncontrolled environments. |
| Web App / SDK | Enable RNNoise for support, sales, healthcare, field, or accessibility workflows. Test clean in-app microphone flows before deciding. |
Troubleshooting
| Symptom | Likely cause | What to do |
|---|---|---|
| Transcript includes background words or sounds | Noise cancellation off or VAD too sensitive | Enable RNNoise and raise VAD threshold. |
| User speech sounds processed or thin | Noise suppression too aggressive for the input | Test with RNNoise disabled for clean microphones. |
| Assistant still interrupts on noise | VAD threshold too low | Raise VAD threshold after enabling RNNoise. |
| STT accuracy is still poor | Wrong language/model, bad input audio, or clipped speech | Check Speech-to-Text and VAD settings. |
Related
Voice Pipeline Overview
Understand where noise cancellation sits in the full pipeline.
Voice Activity Detection
Tune speech detection after noise cancellation.
Speech-to-Text
Choose the transcription provider and model.
End of Speech Detection
Tune turn completion after VAD and STT.