---
title: "Calculate AVQI metrics from connected speech and sustained vowel audio recordings"
method: GET
path: "/api/calculate-avqi"
tags: ["Voice Quality Metrics"]
---

# Calculate AVQI metrics from connected speech and sustained vowel audio recordings

`GET /api/calculate-avqi`

## Request

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

## Query parameters

- `csFileId` string, required
- `svFileId` string, required
- `version` string, required

## Response `200`

Successful response

- object
  - `AVQI` number: Acoustic Voice Quality Index - final composite score (0-10 scale, dimensionless). Values above the language-specific cut-off indicate probable dysphonia; to our knowledge, no validated severity bands exist
  - `CPPS` string: Smoothed Cepstral Peak Prominence measuring harmonic structure (dB). Higher values indicate better periodicity and voice quality
  - `HNR` string: Mean Harmonics-to-Noise Ratio across concatenated CS+SV signal (dB). Higher values indicate less noise relative to harmonic content
  - `Shimmer` number: Period-to-period amplitude variation expressed as percentage (%). Lower values indicate more stable amplitude control
  - `Shimmer_dB` string: Period-to-period amplitude variation in logarithmic scale (dB). Lower values indicate better amplitude stability
  - `LTAS_slope` number: Spectral slope between 0-1kHz and 1-10kHz frequency ranges (dB). More negative values indicate steeper spectral roll-off
  - `LTAS_tilt` string: Spectral tilt of trend line through long-term average spectrum 1-10kHz (dB). Indicates overall spectral balance and voice quality

## 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)