Noise cancellation - rapida.ai documentation

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.

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.

You may disable or avoid it when:

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.

Do not use noise cancellation to hide poor microphone placement, severe clipping, or echo. It can reduce background noise, but it cannot recover speech that was not captured clearly.

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.

See Voice Activity Detection for VAD provider and threshold details.

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.

Listen

Understand where noise cancellation sits in speech input configuration.

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.

​Provider

​When to use it

​How it affects the pipeline

​Tuning with VAD

​Channel guidance

​Troubleshooting

​Related

Listen

Voice Activity Detection

Speech-to-Text

End of Speech Detection

Provider

When to use it

How it affects the pipeline

Tuning with VAD

Channel guidance

Troubleshooting

Related