---
title: "Calculate advanced spectral measures with age and gender-specific clinical interpretation"
method: GET
path: "/api/calculate-spectral-advanced"
tags: ["Advanced Voice Analysis"]
---

# Calculate advanced spectral measures with age and gender-specific clinical interpretation

`GET /api/calculate-spectral-advanced`

## Request

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

## Query parameters

- `svFileId` string, required
- `age` integer, required
- `gender` 1 | 2 | 3, required
- `version` string

## Response `200`

Successful response

- object
  - `SPECTRAL_MEAN` number: Weighted average frequency (center of gravity) in Hz. Example: 1847.3
  - `SPECTRAL_SD` number: Standard deviation of spectral distribution in Hz. Example: 623.8
  - `SPECTRAL_SKEWNESS` number: Third moment indicating spectral asymmetry. Example: 0.85
  - `SPECTRAL_KURTOSIS` number: Fourth moment indicating spectral peakedness. Example: 2.34
  - `ALPHA_RATIO` number: Energy ratio below/above 1 kHz in dB. Example: 4.2
  - `L1_L0` number: First formant to fundamental energy difference in dB. Example: -8.5
  - `H1_H2` number: First to second harmonic amplitude difference in dB. Example: 3.8
  - `H1_A1` number: First harmonic to first formant amplitude difference in dB. Example: -5.2
  - `H1_A3` number: First harmonic to third formant amplitude difference in dB. Example: -15.7
  - `SPECTRAL_FLUX` number: Rate of spectral change in Hz. Example: 234.6
  - `LTAS_SLOPE` number: Spectral slope 0-1 kHz vs 1-4 kHz in dB. Example: -12.4
  - `LTAS_TILT` number: Trend line slope across 1-4 kHz in dB. Example: -8.9
  - `LTAS_CURVE` number: Full Long-Term Average Spectrum as freq/dB pairs, 80-4000 Hz in 100 Hz steps. Example: [{"freq":80,"db":-25.3}, ...]
  - `MEAN_F0` number: Mean fundamental frequency in Hz. Example: 195.8
  - `F1_MEAN` number: Mean first formant frequency in Hz. Example: 685.4
  - `F2_MEAN` number: Mean second formant frequency in Hz. Example: 1247.8
  - `F3_MEAN` number: Mean third formant frequency in Hz. Example: 2856.1
  - `GENDER` string: Gender classification result. Example: "Female"
  - `VOICE_PATTERN` string: Clinical classification. Example: "Balanced voice pattern"
  - `BREATHINESS_LEVEL` string: Breathiness assessment. Example: "Minimal breathiness"
  - `VOICE_STABILITY` string: Stability classification. Example: "Good stability"
  - `SPECTRAL_HEALTH` string: Overall spectral assessment. Example: "Healthy spectral characteristics"
  - `PATIENT_AGE` integer: Patient age used in analysis. Example: 35
  - `PATIENT_GENDER` string: Patient gender classification. Example: "Female"
  - `AGE_GROUP` string: Age group classification. Example: "Young Adult"
  - `AGE_NOTE` string: Age-related clinical note. Example: "Age within normal vocal range"
  - `F0_NOTE` string: F0 validation note. Example: "F0 within expected range"
  - `F0_VALIDITY` string: F0 validation status. Example: "Valid"
  - `GENDER_SPECTRAL_NOTE` string: Gender-specific spectral note. Example: "Female spectral characteristics confirmed"
  - `EXPECTED_F0_MIN` number: Expected minimum F0 for age/gender. Example: 165.4
  - `EXPECTED_F0_MAX` number: Expected maximum F0 for age/gender. Example: 294.3
  - `SPECTRAL_MEAN_EXPECTED` number: Expected spectral mean for demographics. Example: 1923.5

## 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)