---
title: BaseAudioContext
slug: Web/API/BaseAudioContext
tags:
- API
- Audio
- BaseAudioContext
- Interface
- NeedsTranslation
- Reference
- TopicStub
- Web Audio API
translation_of: Web/API/BaseAudioContext
---
{{APIRef("Web Audio API")}}
The BaseAudioContext
interface acts as a base definition for online and offline audio-processing graphs, as represented by {{domxref("AudioContext")}} and {{domxref("OfflineAudioContext")}} respectively. You wouldn't use BaseAudioContext
directly — you'd use its features via one of these two inheriting interfaces.
A BaseAudioContext
can be a target of events, therefore it implements the {{domxref("EventTarget")}} interface.
{{InheritanceDiagram}}
Properties
- {{domxref("BaseAudioContext.audioWorklet")}} {{experimental_inline}} {{readonlyInline}}
- Returns the {{domxref("AudioWorklet")}} object, used for creating custom AudioNodes with JavaScript processing.
- {{domxref("BaseAudioContext.currentTime")}} {{readonlyInline}}
- Returns a double representing an ever-increasing hardware time in seconds used for scheduling. It starts at
0
.
- {{domxref("BaseAudioContext.destination")}} {{readonlyInline}}
- Returns an {{domxref("AudioDestinationNode")}} representing the final destination of all audio in the context. It can be thought of as the audio-rendering device.
- {{domxref("BaseAudioContext.listener")}} {{readonlyInline}}
- Returns the {{domxref("AudioListener")}} object, used for 3D spatialization.
- {{domxref("BaseAudioContext.sampleRate")}} {{readonlyInline}}
- Returns a float representing the sample rate (in samples per second) used by all nodes in this context. The sample-rate of an {{domxref("AudioContext")}} cannot be changed.
- {{domxref("BaseAudioContext.state")}} {{readonlyInline}}
- Returns the current state of the
AudioContext
.
Event handlers
- {{domxref("BaseAudioContext.onstatechange")}}
- An event handler that runs when an event of type {{event("statechange")}} has fired. This occurs when the
AudioContext
's state changes, due to the calling of one of the state change methods ({{domxref("AudioContext.suspend")}}, {{domxref("AudioContext.resume")}}, or {{domxref("AudioContext.close")}}).
Methods
Also implements methods from the interface {{domxref("EventTarget")}}.
- {{domxref("BaseAudioContext.createBuffer()")}}
- Creates a new, empty {{ domxref("AudioBuffer") }} object, which can then be populated by data and played via an {{ domxref("AudioBufferSourceNode") }}.
- {{domxref("BaseAudioContext.createConstantSource()")}}
- Creates a {{domxref("ConstantSourceNode")}} object, which is an audio source that continuously outputs a monaural (one-channel) sound signal whose samples all have the same value.
- {{domxref("BaseAudioContext.createBufferSource()")}}
- Creates an {{domxref("AudioBufferSourceNode")}}, which can be used to play and manipulate audio data contained within an {{ domxref("AudioBuffer") }} object. {{ domxref("AudioBuffer") }}s are created using {{domxref("AudioContext.createBuffer")}} or returned by {{domxref("AudioContext.decodeAudioData")}} when it successfully decodes an audio track.
- {{domxref("BaseAudioContext.createScriptProcessor()")}}
- Creates a {{domxref("ScriptProcessorNode")}}, which can be used for direct audio processing via JavaScript.
- {{domxref("BaseAudioContext.createStereoPanner()")}}
- Creates a {{domxref("StereoPannerNode")}}, which can be used to apply stereo panning to an audio source.
- {{domxref("BaseAudioContext.createAnalyser()")}}
- Creates an {{domxref("AnalyserNode")}}, which can be used to expose audio time and frequency data and for example to create data visualisations.
- {{domxref("BaseAudioContext.createBiquadFilter()")}}
- Creates a {{domxref("BiquadFilterNode")}}, which represents a second order filter configurable as several different common filter types: high-pass, low-pass, band-pass, etc.
- {{domxref("BaseAudioContext.createChannelMerger()")}}
- Creates a {{domxref("ChannelMergerNode")}}, which is used to combine channels from multiple audio streams into a single audio stream.
- {{domxref("BaseAudioContext.createChannelSplitter()")}}
- Creates a {{domxref("ChannelSplitterNode")}}, which is used to access the individual channels of an audio stream and process them separately.
- {{domxref("BaseAudioContext.createConvolver()")}}
- Creates a {{domxref("ConvolverNode")}}, which can be used to apply convolution effects to your audio graph, for example a reverberation effect.
- {{domxref("BaseAudioContext.createDelay()")}}
- Creates a {{domxref("DelayNode")}}, which is used to delay the incoming audio signal by a certain amount. This node is also useful to create feedback loops in a Web Audio API graph.
- {{domxref("BaseAudioContext.createDynamicsCompressor()")}}
- Creates a {{domxref("DynamicsCompressorNode")}}, which can be used to apply acoustic compression to an audio signal.
- {{domxref("BaseAudioContext.createGain()")}}
- Creates a {{domxref("GainNode")}}, which can be used to control the overall volume of the audio graph.
- {{domxref("BaseAudioContext.createIIRFilter()")}}
- Creates an {{domxref("IIRFilterNode")}}, which represents a second order filter configurable as several different common filter types.
- {{domxref("BaseAudioContext.createOscillator()")}}
- Creates an {{domxref("OscillatorNode")}}, a source representing a periodic waveform. It basically generates a tone.
- {{domxref("BaseAudioContext.createPanner()")}}
- Creates a {{domxref("PannerNode")}}, which is used to spatialise an incoming audio stream in 3D space.
- {{domxref("BaseAudioContext.createPeriodicWave()")}}
- Creates a {{domxref("PeriodicWave")}}, used to define a periodic waveform that can be used to determine the output of an {{ domxref("OscillatorNode") }}.
- {{domxref("BaseAudioContext.createWaveShaper()")}}
- Creates a {{domxref("WaveShaperNode")}}, which is used to implement non-linear distortion effects.
- {{domxref("BaseAudioContext.decodeAudioData()")}}
- Asynchronously decodes audio file data contained in an {{domxref("ArrayBuffer")}}. In this case, the ArrayBuffer is usually loaded from an {{domxref("XMLHttpRequest")}}'s
response
attribute after setting the responseType
to arraybuffer
. This method only works on complete files, not fragments of audio files.
- {{domxref("BaseAudioContext.resume()")}}
- Resumes the progression of time in an audio context that has previously been suspended/paused.
Examples
Basic audio context declaration:
var audioCtx = new AudioContext();
Cross browser variant:
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();
var oscillatorNode = audioCtx.createOscillator();
var gainNode = audioCtx.createGain();
var finish = audioCtx.destination;
// etc.
Specifications
Specification |
Status |
Comment |
{{SpecName('Web Audio API', '#BaseAudioContext', 'BaseAudioContext')}} |
{{Spec2('Web Audio API')}} |
|
Browser compatibility
{{CompatibilityTable}}
Feature |
Chrome |
Edge |
Firefox (Gecko) |
Internet Explorer |
Opera |
Safari (WebKit) |
Basic support |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatNo}} |
15.0{{property_prefix("webkit")}}
22 |
6.0{{property_prefix("webkit")}} |
baseLatency |
{{CompatChrome(60)}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
createConstantSource() |
{{CompatChrome(56)}} |
{{CompatNo}} |
{{CompatGeckoDesktop(52)}} |
{{CompatNo}} |
{{CompatOpera(43)}} |
{{CompatNo}} |
createStereoPanner() |
{{CompatChrome(42)}} |
{{CompatVersionUnknown}} |
{{CompatGeckoDesktop(37.0)}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatNo}} |
onstatechange , state , suspend() , resume() |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatGeckoDesktop(40.0)}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatSafari(8.0)}} |
Unprefixed |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
|
|
|
|
Feature |
Android Webview |
Chrome for Android |
Edge |
Firefox Mobile (Gecko) |
Firefox OS |
IE Mobile |
Opera Mobile |
Safari Mobile |
Basic support |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
2.2 |
{{CompatNo}} |
{{CompatVersionUnknown}} |
{{CompatNo}} |
baseLatency |
{{CompatChrome(60)}} |
{{CompatChrome(60)}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
createConstantSource() |
{{CompatChrome(56)}} |
{{CompatChrome(56)}} |
{{CompatNo}} |
{{CompatGeckoMobile(52)}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatNo}} |
createStereoPanner() |
{{CompatChrome(42)}} |
{{CompatChrome(42)}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatNo}} |
onstatechange , state , suspend() , resume() |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatNo}} |
{{CompatNo}} |
{{CompatNo}} |
Unprefixed |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatVersionUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatUnknown}} |
{{CompatOperaMobile(43)}} |
{{CompatUnknown}} |
See also