# Audio Recording Development ## When to Use During audio recording, audio signals are recorded and saved. You can set the sampling rate, number of audio channels, bit rate, encoding format, encapsulation format, and file path for audio recording. ## Available APIs **Table 1** APIs for audio recording

API	Description
media.createAudioRecorder()	Creates an AudioRecorder instance.
AudioRecorder	Provides audio recording methods.
AudioRecorderConfig	Provides parameters related to audio recording.

**Table 2** AudioRecorder methods

Method	Description
prepare(config: AudioRecorderConfig): void	Prepares for audio recording and sets parameters.
start(): void	Starts audio recording.
pause(): void	Pauses audio recording. (Not supported yet)
resume(): void	Resumes audio recording. (Not supported yet)
stop(): void	Stops audio recording.
release(): void	Releases audio recording resources.
reset(): void	Resets audio recording.
on('prepare', function callback)	Subscribes to the audio recording preparation event.
on('start', function callback)	Subscribes to the audio recording start event.
on('pause', function callback)	Subscribes to the audio recording pause event.
on('resume', function callback)	Subscribes to the audio recording resumption event.
on('stop',function callback)	Subscribes to the audio recording end event.
on('release', function callback)	Subscribes to the event of releasing audio recording resources.
on('reset', function callback)	Subscribes to the audio recording reset event.
on('error', function callback)	Subscribes to the audio recording error event.

**Table 3** AudioRecorderConfig

API	Description
audioEncoder?: AudioEncoder	Audio encoding format. The default value is AAC_LC.
audioEncodeBitRate?: number	Bit rate for audio encoding. The default value is 48000.
audioSampleRate?: number	Sampling rate for audio encoding. The default value is 48000.
numberOfChannels?: number	Number of audio channels. The default value is 2.
format?: AudioOutputFormat	Audio output format. The default value is MPEG_4.
uri: string	Audio output path, which starts with file://path or file://fd.

**Table 4** AudioEncoder

API	Description
AAC_LC = 3	AAC_LC format.

**Table 5** AudioOutputFormat

API	Description
MPEG_4 = 2	MPEG-4 format.
AAC_ADTS= 6	AAC_ADTS format.

1. Create an audio recorder. ``` import media from '@ohos.multimedia.media'; var recorder = media.createAudioRecorder(); ``` 2. Prepare for audio recording and set parameters. ``` let audioRecorderConfig = { audioEncoder : AAC_LC , audioEncodeBitRate : 22050, audioSampleRate : 22050, numberOfChannels : 2, format : AAC_ADTS, uri : 'file:///data/accounts/account_0/appdata/appdata/recorder/test.m4a', } recorder.prepare(audioRecorderConfig); ``` 3. Set the subscription events. ``` recorder.on('prepare', () => { console.info('setCallback prepare() case callback is called'); recorder.start(); }); recorder.on('start', () => { console.info('setCallback start() case callback is called'); setTimeout(function(){ recorder.pause(); }, 10000); // Pause recording 10 seconds after the recording starts. }); recorder.on('pause', () => { console.info('setCallback pause() case callback is called'); setTimeout(function(){ recorder.resume(); }, 10000); // Resume recording 10 seconds after the recording is paused. }); recorder.on('resume', () => { console.info('setCallback resume() case callback is called'); setTimeout(function(){ recorder.stop(); }, 10000); // Stop recording 10 seconds after the recording is resumed. }); recorder.on('stop', () => { console.info('setCallback stop() case callback is called'); recorder.release(); }); recorder.on('release', () => { console.info('setCallback release() case callback is called'); }); recorder.on('error', (err) => { console.info(`case error called,errCode is ${err.code}`); console.info(`case error called,errMessage is ${err.message}`); recorder.reset(); }); ```