AmplitudeData

Info

AmplitudeData contains the amplitude analysis results from the current audio frame. It provides both the RMS (root mean square) amplitude for perceived loudness and the peak amplitude for maximum signal level. This is one of three analysis dimensions returned by AudioAnalysisResult.

Properties

Property	Type	Description
rms	number	Root mean square amplitude — a measure of perceived loudness. Typically ranges from 0.0 (silence) to 1.0 (maximum).
peak	number	Peak amplitude — the maximum signal level in the current frame. Ranges from 0.0 to 1.0.

Note

RMS amplitude is a better indicator of perceived loudness than peak amplitude, as it averages the signal over time. Peak amplitude captures the maximum instantaneous level, which is useful for detecting clipping or sharp transients.

Usage

AmplitudeData is accessed via result.amplitude on an AudioAnalysisResult object. Use it for:

• Volume level meters and VU displays
• Detecting silence or loud passages
• Audio-reactive visualizations (e.g. pulsing effects based on loudness)
• Clipping detection when peak approaches 1.0

Tips

For a simple volume meter, use rms — it represents perceived loudness more accurately than peak. Use peak only when you need to detect the absolute maximum signal level, such as for clipping prevention.

Example

TypeScript

import { getResult, AmplitudeData } from '@eisland/windows-volume-analyzer';

const result = getResult();
const amp: AmplitudeData = result.amplitude;

// Simple volume meter (0–10 scale)
const meter = Math.round(amp.rms * 10);
console.log(`Volume: ${'█'.repeat(meter)}${'░'.repeat(10 - meter)} ${(amp.rms * 100).toFixed(0)}%`);

// Detect clipping
if (amp.peak >= 0.99) {
  console.warn('Audio clipping detected!');
}

// Detect silence
if (amp.rms < 0.001) {
  console.log('Silence detected');
}

JavaScript

const { getResult } = require('@eisland/windows-volume-analyzer');

const result = getResult();
const amp = result.amplitude;

// Simple volume meter (0–10 scale)
const meter = Math.round(amp.rms * 10);
console.log(`Volume: ${'█'.repeat(meter)}${'░'.repeat(10 - meter)} ${(amp.rms * 100).toFixed(0)}%`);

// Detect clipping
if (amp.peak >= 0.99) {
  console.warn('Audio clipping detected!');
}

// Detect silence
if (amp.rms < 0.001) {
  console.log('Silence detected');
}

Notes

Note

Both rms and peak are normalized to the range 0.0–1.0. A value of 0.0 indicates silence, while 1.0 represents the maximum digital signal level.

Tips

When building audio-reactive UIs, apply a smoothing or easing function to rms to avoid jittery visual updates. Raw rms values can fluctuate rapidly between frames.

Important

Amplitude values are derived from the WASAPI loopback capture of the target process. They represent the audio output of that specific process, not the system-wide volume.

Danger Avoidance

Caution

Do not use peak as a proxy for loudness in UI displays. Peak amplitude captures instantaneous spikes and will appear much louder than the perceived volume. Use rms for loudness visualization and peak only for clipping detection.