---
title: "Calculate the Cepstral Spectral Index of Dysphonia (CSID) from a connected speech recording pre-uploaded via POST /ap…"
method: GET
path: "/api/calculate-csid"
tags: ["Advanced Voice Analysis"]
---

# Calculate the Cepstral Spectral Index of Dysphonia (CSID) from a connected speech recording pre-uploaded via POST /ap…

`GET /api/calculate-csid`

## Request

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

## Query parameters

- `csFileId` string, required

## Response `200`

Successful response

- object
  - `CSID_SCORE` number: number - CSID score (154.59 − 10.393·CPP − 1.083·SR − 3.713·SR_SD).
  - `CPP` number: number - Smoothed cepstral peak prominence over the whole signal, in dB.
  - `SR` number: number - Low/high spectral ratio (energy below 4 kHz vs 4–8 kHz), in dB, averaged over voiced frames.
  - `SR_SD` number: number - Standard deviation of the spectral ratio across voiced frames, in dB.
  - `N_VOICED_FRAMES` integer: integer - Number of voiced frames used.
  - `CUTOFF_SCREENING` number: number - Screening cut-off (19.09).
  - `CUTOFF_BALANCED` number: number - Balanced cut-off (24.27).
  - `CUTOFF_CONSERVATIVE` number: number - Conservative cut-off (30.85).
  - `CSID_REFERENCE` string: Bibliographic reference of the formula (Awan et al.).
  - `CSID_CAVEAT` string: Note on the per-frame approximation used by this implementation.

## 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)