---
title: Functions
order: 1
summary: Every function of the module, by area.
---

<!-- Generated by tools/generate-docs.bxs. Do not edit. -->

All 68 functions of the module. Audio is passed around as an audio buffer: every function that changes audio returns a new buffer and leaves the one you gave it alone.

| Function | Area | |
|---|---|---|
| [`audioAdd`](timeline.md) | Timeline mixing | Place a sound on a timeline track |
| [`audioBeats`](timeline.md) | Timeline mixing | List moments on the beat grid of a timeline, in seconds |
| [`audioBpm`](analysis.md) | Analysis | Detect the tempo of audio and where its beats fall |
| [`audioChannels`](files-and-editing.md) | Files and editing | Convert an audio buffer between mono and stereo. |
| [`audioChorus`](effects.md) | Effects | Thicken and widen an audio buffer with a chorus |
| [`audioCompress`](loudness-and-dynamics.md) | Loudness and dynamics | Reduce the dynamic range of audio with a compressor |
| [`audioConcat`](files-and-editing.md) | Files and editing | Join audio buffers end to end. |
| [`audioDelay`](effects.md) | Effects | Add an echo to an audio buffer |
| [`audioDetectSilence`](analysis.md) | Analysis | Find the silent stretches of audio |
| [`audioDrum`](synthesis.md) | Synthesis | Synthesise a drum hit |
| [`audioDuck`](timeline.md) | Timeline mixing | Duck a timeline track while another track is loud, like music under a voice-over |
| [`audioEnvelope`](synthesis.md) | Synthesis | Shape the volume of a sound with an attack and an exponential decay |
| [`audioEq`](loudness-and-dynamics.md) | Loudness and dynamics | Shape the tone of audio with parametric equalizer bands |
| [`audioFade`](files-and-editing.md) | Files and editing | Fade an audio buffer in and out. |
| [`audioFfmpegInstall`](ffmpeg-and-video.md) | FFmpeg and video | Download FFmpeg for this computer into the bx-audio home, checked against a pinned checksum |
| [`audioFfmpeg`](ffmpeg-and-video.md) | FFmpeg and video | Find FFmpeg on this computer and say what it can do: OGG, Opus, AAC and video files need it |
| [`audioFft`](analysis.md) | Analysis | Get the frequency spectrum of one window of audio |
| [`audioFilter`](synthesis.md) | Synthesis | Filter an audio buffer with a low-pass, high-pass, band-pass or notch filter |
| [`audioFitTo`](time-and-pitch.md) | Time and pitch | Change the length of audio to a number of seconds without changing its pitch |
| [`audioFreq`](synthesis.md) | Synthesis | Convert a note name or MIDI number to a frequency in Hz |
| [`audioGain`](files-and-editing.md) | Files and editing | Change the volume of an audio buffer. |
| [`audioInfo`](files-and-editing.md) | Files and editing | Describes some audio. |
| [`audioLicenses`](speech.md) | Speech and subtitles | List the licenses of the offered voices and what each asks of you. |
| [`audioLimit`](loudness-and-dynamics.md) | Loudness and dynamics | Stop audio from going above a ceiling with a look-ahead limiter |
| [`audioLoad`](files-and-editing.md) | Files and editing | Reads an audio file fully into memory. |
| [`audioLoopify`](games.md) | Game audio | Make a sound loop seamlessly by blending its end into its start |
| [`audioLoudness`](loudness-and-dynamics.md) | Loudness and dynamics | Measure the loudness of audio as EBU R128 does: integrated LUFS, loudness range, true peak |
| [`audioMarkers`](ffmpeg-and-video.md) | FFmpeg and video | Write markers (points in time with labels) as JSON, CSV, a Resolve EDL, SRT, WebVTT, FFmpeg chapters or a YouTube chapter list |
| [`audioMaster`](loudness-and-dynamics.md) | Loudness and dynamics | Master audio for delivery: reach a loudness target with a true-peak ceiling, optionally gluing the mix with light compression |
| [`audioMix`](files-and-editing.md) | Files and editing | Add audio buffers together so they play at the same time |
| [`audioMixer`](games.md) | Game audio | Open a real time mixer that plays many sounds at once with volume, pan, pitch, loops and buses, the way a game needs |
| [`audioMux`](ffmpeg-and-video.md) | FFmpeg and video | Put audio on a video file, copying the picture without re-encoding it |
| [`audioNoise`](synthesis.md) | Synthesis | Generate repeatable noise |
| [`audioNormalizeLoudness`](loudness-and-dynamics.md) | Loudness and dynamics | Set the integrated loudness of audio to a target in LUFS, keeping peaks under a true-peak ceiling |
| [`audioNormalize`](files-and-editing.md) | Files and editing | Scale an audio buffer so its peak hits a target level. |
| [`audioOsc`](synthesis.md) | Synthesis | Generate a tone with an oscillator |
| [`audioPan`](files-and-editing.md) | Files and editing | Position an audio buffer in the stereo field. |
| [`audioPitch`](time-and-pitch.md) | Time and pitch | Change the pitch of audio without changing its length |
| [`audioPlay`](games.md) | Game audio | Play audio through the speakers |
| [`audioPump`](timeline.md) | Timeline mixing | Duck a timeline track at given moments, like a kick drum sidechain |
| [`audioRender`](timeline.md) | Timeline mixing | Mix a timeline down to one audio buffer |
| [`audioResample`](files-and-editing.md) | Files and editing | Change the sample rate of an audio buffer. |
| [`audioReverb`](effects.md) | Effects | Add reverb to an audio buffer |
| [`audioReverse`](files-and-editing.md) | Files and editing | Reverse an audio buffer. |
| [`audioSaturate`](effects.md) | Effects | Round off peaks with a warm limiting curve |
| [`audioSave`](files-and-editing.md) | Files and editing | Writes an audio buffer to a file, replacing any existing file. |
| [`audioSilence`](files-and-editing.md) | Files and editing | Creates an audio buffer filled with silence. |
| [`audioSpeakCues`](speech.md) | Speech and subtitles | Speak a text piece by piece and return the audio with the time each caption line is spoken |
| [`audioSpeak`](speech.md) | Speech and subtitles | Turn text into speech with an installed Piper voice, installing the engine and the voice on first use |
| [`audioSpectrogram`](analysis.md) | Analysis | Get the band levels of audio over time, for drawing or analysis |
| [`audioSpectrum`](analysis.md) | Analysis | Get the level of audio in log spaced frequency bands, in dB |
| [`audioSpeechStatus`](speech.md) | Speech and subtitles | Describe the text to speech setup: where it lives, whether the engine is installed, and which voices are |
| [`audioSprite`](games.md) | Game audio | Join named sounds into one audio sprite with a map of where each starts, the way Howler.js and game engines load effects |
| [`audioStorageClear`](storage.md) | Storage | Delete downloaded engine, voices, FFmpeg or cached files from the bx-audio home |
| [`audioStorage`](storage.md) | Storage | Show where bx-audio keeps its downloaded engine, voices and tools, and how big they are |
| [`audioStretch`](time-and-pitch.md) | Time and pitch | Change the speed of audio without changing its pitch |
| [`audioSubtitles`](speech.md) | Speech and subtitles | Write captions as SRT or WebVTT subtitles for a video |
| [`audioSweep`](synthesis.md) | Synthesis | Generate a sine that glides from one pitch to another |
| [`audioTimeline`](timeline.md) | Timeline mixing | Create a multi track timeline for mixing sounds |
| [`audioTrackGain`](timeline.md) | Timeline mixing | Set the volume of a whole timeline track |
| [`audioTrimSilence`](analysis.md) | Analysis | Cut the silence off the start and the end of audio |
| [`audioTrim`](files-and-editing.md) | Files and editing | Cut a section out of an audio buffer. |
| [`audioVariations`](games.md) | Game audio | Make several slightly different copies of a sound, so repeated effects do not sound the same |
| [`audioVoiceInstall`](speech.md) | Speech and subtitles | Download a voice, or the text to speech engine itself, and check it |
| [`audioVoiceRemove`](speech.md) | Speech and subtitles | Delete an installed voice, or the text to speech engine, from disk |
| [`audioVoices`](speech.md) | Speech and subtitles | List the voices of the collection, with their licenses and what you can do with each |
| [`audioWaveform`](files-and-editing.md) | Files and editing | Summarize audio as a list of peak levels for drawing a waveform. |
| [`videoInfo`](ffmpeg-and-video.md) | FFmpeg and video | Describe any audio or video file with FFprobe: length, size, and the video and audio streams |