---
title: "Noise Suppression Start (BETA)"
method: POST
path: "/calls/{call_control_id}/actions/suppression_start"
tags: ["Call Commands"]
---

# Noise Suppression Start (BETA)

`POST /calls/{call_control_id}/actions/suppression_start`

## Path parameters

- `call_control_id` string, required

## Request body

- NoiseSuppressionStart
  - `client_state` string — Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string.
  - `command_id` string — Use this field to avoid duplicate commands. Telnyx will ignore any command with the same `command_id` for the same `call_control_id`.
  - `direction` 'inbound' | 'outbound' | 'both' — The direction of the audio stream to be noise suppressed.
  - `noise_suppression_engine` 'Denoiser' | 'DeepFilterNet' | 'Krisp' | 'AiCoustics' | 'aic_l_quail' | 'aic_l_rook' | 'aic_s_quail' | 'aic_s_rook' | 'quail_voice_focus_s' | 'quail_voice_focus_xs' — The engine to use for noise suppression. For backward compatibility, engines A, B, C, and D are also supported, but are deprecated: A - Denoiser B - DeepFilterNet C - Krisp D - AiCoustics
  - `noise_suppression_engine_config` NoiseSuppressionEngineConfig — Configuration parameters for noise suppression engines. Different engines support different parameters.
    - `attenuation_limit` integer — The attenuation limit for noise suppression (0-100). Only applicable for DeepFilterNet.
    - `mode` 'standard' | 'advanced' — Processing mode. Only applicable for DeepFilterNet.
    - `model` 'krisp-viva-tel-v2.kef' | 'krisp-viva-tel-lite-v1.kef' | 'krisp-viva-pro-v1.kef' | 'krisp-viva-ss-v1.kef' — The Krisp model to use. Only applicable for Krisp.
    - `suppression_level` number — Suppression level (0.0-100.0). Only applicable for Krisp.
    - `family` 'sparrow' | 'quail' — AiCoustics model family. 'sparrow' optimized for human-to-human calls, 'quail' optimized for Voice AI/STT. Only applicable for AiCoustics.
    - `size` 's' | 'l' | 'xs' | 'xxs' | 'vf_l' | 'vf_1_1_l' — AiCoustics model size. 's' and 'l' work with both families. 'xs' and 'xxs' are sparrow-only. 'vf_l' and 'vf_1_1_l' are quail-only. Only applicable for AiCoustics.
    - `enhancement_level` number — Enhancement intensity (0.0-1.0). Only applicable for AiCoustics.
    - `voice_gain` number — Voice gain multiplier (0.1-4.0). Only applicable for AiCoustics.

## Response `200`

Successful response upon making a call control command.

- object
  - `data` CallControlCommandResult
    - `result` string

## Other responses

- `422` — Unprocessable entity. The request was well-formed but could not be processed due to semantic errors. This includes validation errors, invalid parameter values, call state errors, conference errors, queue errors, recording/transcription errors, and business logic violations.
- `default` — Unexpected error

---

[API](https://skmtc.net/team-telnyx/apis/telnyx-api-2.md) · [All operations](https://skmtc.net/team-telnyx/apis/telnyx-api-2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/team-telnyx/telnyx-api-2/versions/8f5f4e537994/schema)