Filter Background Noise from Calls - Dasha BlackBox Documentation

Filter out background noise from incoming audio so your agent hears speech clearly — even when callers are in noisy environments. Uses Krisp’s AI-powered noise suppression engine. What you’ll learn: How to enable noise suppression, configure suppression levels, and choose recording strategies.

Krisp noise suppression incurs an additional per-minute fee.

When to use noise suppression

Environment	Without suppression	With suppression
Street/traffic	Agent mishears words, frequent “could you repeat that”	Clear speech isolation
Cafe/restaurant	Background chatter confuses STT	Voice stands out from ambiance
Construction site	Heavy machinery drowns out caller	Speech remains intelligible
Home with kids/pets	Barking, crying triggers false transcriptions	Focuses on primary speaker

Noise suppression improves speech-to-text accuracy by removing non-voice audio before it reaches the transcription engine.

Configure noise suppression

Dashboard
API

Open your agent’s configuration
Navigate to the Features tab
Find Noise Suppression and toggle it on
Select Krisp as the engine
Adjust the suppression level (0–100)
Choose recording strategy (raw or cleaned)
Save your agent

const response = await fetch('https://blackbox.dasha.ai/api/v1/agents', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    name: 'Support Agent',
    config: {
      features: {
        noiseSuppression: {
          isEnabled: true,
          type: 'krisp',
          noiseSuppressionLevel: 75,
          recordWriteStrategy: 'raw'
        }
      }
      // ... other config
    }
  })
});

Configuration options

Field	Type	Default	Description
`isEnabled`	boolean	`false`	Master toggle for noise suppression
`type`	string	`"none"`	Engine: `"none"` or `"krisp"`
`noiseSuppressionLevel`	integer	`75`	Aggressiveness (0–100)
`recordWriteStrategy`	string	`"raw"`	What to save: `"raw"` or `"cleaned"`

Suppression levels

The noiseSuppressionLevel controls how aggressively background noise is filtered:

Level	Effect	Best for
0–30	Light filtering	Quiet environments with occasional noise
40–60	Moderate filtering	Office or home settings
70–85	Strong filtering	Busy public spaces (default: 75)
90–100	Maximum filtering	Extremely noisy environments

Very high levels (90+) may slightly affect voice quality. Start at 75 and adjust based on your use case.

Recording strategy

Choose what audio gets saved in call recordings:

Strategy	Saves	Use when
raw	Original unprocessed audio	You need the authentic recording for compliance or disputes
cleaned	Noise-suppressed audio	You want cleaner recordings for review or training

Example: Compliance-first (raw recordings)

noiseSuppression: {
  isEnabled: true,
  type: 'krisp',
  noiseSuppressionLevel: 75,
  recordWriteStrategy: 'raw'  // Keep original audio for legal purposes
}

Example: Clean recordings for QA

noiseSuppression: {
  isEnabled: true,
  type: 'krisp',
  noiseSuppressionLevel: 80,
  recordWriteStrategy: 'cleaned'  // Save the cleaned version
}

How it works

Caller audio arrives with background noise
Krisp engine processes the audio in real-time
Cleaned audio goes to STT for accurate transcription
Recording saves either raw or cleaned audio (your choice)

The agent always hears the cleaned audio. The recording strategy only affects what gets stored.

Troubleshooting

Agent still mishearing in noisy environments

Symptom	Fix
Suppression enabled but no improvement	Verify `type` is set to `"krisp"`, not `"none"`
Some noise gets through	Increase `noiseSuppressionLevel` to 85–90
Extreme noise environments	Level 100 + consider if call quality is viable

Voice sounds distorted

Symptom	Fix
Voice sounds robotic or thin	Lower `noiseSuppressionLevel` to 60–70
Words getting cut off	Reduce level; aggressive filtering can clip speech

Next steps

Ambient Noise

Add background sounds (outgoing)

Voice & Speech

Configure STT and TTS

Language Switching

Support multiple languages

Call Inspector

Debug call audio issues

Documentation Index

​When to use noise suppression

​Configure noise suppression

​Configuration options

​Suppression levels

​Recording strategy

​How it works

​Troubleshooting

​Agent still mishearing in noisy environments

​Voice sounds distorted

​Next steps

Ambient Noise

Voice & Speech

Language Switching

Call Inspector

When to use noise suppression

Configure noise suppression

Configuration options

Suppression levels

Recording strategy

How it works

Troubleshooting

Agent still mishearing in noisy environments

Voice sounds distorted

Next steps