--- 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