---
title: "Measure the sound level (dB SPL) of an audio recording over a specified time window. Useful for environmental noise c…"
method: POST
path: "/api/soundLevel"
tags: ["Audio Measures"]
---

# Measure the sound level (dB SPL) of an audio recording over a specified time window. Useful for environmental noise c…

`POST /api/soundLevel`

## Request

- Base URL: `https://platform.vocametrix.com`
- URL: `https://platform.vocametrix.com/api/soundLevel`
- Auth: API key in header `X-API-Key`

## Request body

- object
  - `blobUrl` string, required: REQUIRED. URL of the audio file (typically obtained via /api/get-blob-url + upload).
  - `start_sec` number, required: REQUIRED. Start of the analysis window in seconds. CAVEAT: The server uses a falsy check (`!start_sec`), so the literal value 0 is rejected — pass a tiny positive value like 0.001 if you mean 'from the beginning'.
  - `stop_sec` number, required: REQUIRED. End of the analysis window in seconds. Must be > start_sec.

## Response `200`

Successful response

- object
  - `soundLevel` number: Number — dB value rounded to 2 decimals.
  - `unit` string: String — currently "dB SPL".
  - `frequencyRange` number: String — currently "20-8000 Hz".

## Other responses

- `400`: Bad request — missing or invalid parameter
- `401`: Unauthorized — missing or invalid API key
- `429`: Rate limit exceeded
- `500`: Server error

---

[API](https://skmtc.dev/vocametrix/apis/vocametrix-api.md) · [All operations](https://skmtc.dev/vocametrix/apis/vocametrix-api/llms.txt) · [OpenAPI document](https://skmtc.dev/vocametrix/apis/vocametrix-api/revisions/8a54d01bcc81?raw)