1. Perceivable · 1.4 Distinguishable

1.4.2 — Audio Control

Level A

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Add audio control

In Android apps you should always be able to control audio. When using MediaPlayer, you should implement buttons to call the start), pause) and stop) methods.

It is a best practice to play audio through the correct channel. Android has introduced AudioAttributes as a replacement of the STREAM types defined in AudioManager.

AudioAttributes defines the following content types:

CONTENT_TYPE_MOVIE: used for soundtracks, typically in movies
CONTENT_TYPE_MUSIC: used for music
CONTENT_TYPE_SONIFICATION: used for accompanying sounds, such as beeps
CONTENT_TYPE_SPEECH: used for speech
CONTENT_TYPE_UNKNOWN: used when the content type is unknown, or other than the available options

AudioAttributes defines the following usages:

USAGE_ALARM: used for alarms
USAGE_ASSISTANCE_ACCESSIBILITY: used for accessibility, e.g. for screen reader users
USAGE_ASSISTANCE_NAVIGATION_GUIDANCE: used for navigation directions, e.g. while driving
USAGE_ASSISTANCE_SONIFICATION: used for user interface sounds
USAGE_ASSISTANT: used for user queries, audio instructions or help utterances.
USAGE_GAME: used for audio inside games
USAGE_MEDIA: used for audio in media, such as movies
USAGE_NOTIFICATION: used for notification sounds
USAGE_NOTIFICATION_EVENT: used to attract the user's attention, such as a reminder or low battery warning.
USAGE_NOTIFICATION_RINGTONE: used for telephony ringtones
USAGE_UNKNOWN: used when the usage is unknown, or not defined
USAGE_VOICE_COMMUNICATION: used for voice communication, such as telephony or VoIP
USAGE_VOICE_COMMUNICATION_SIGNALLING: used for in-call signalling, such as with a "busy" beep, or DTMF tones.

AudioManager defines the following legacy channels:

STREAM_ACCESSIBILITY: channel for accessibility, such as assistive technologies
STREAM_ALARM: channel for alarms
STREAM_DMTF: channel for dual-tone multi-frequency signaling, such as phone dialing tones
STREAM_MUSIC: channel for music
STREAM_NOTIFICATION: channel for notifications
STREAM_RING: channel for incoming phone calls
STREAM_SYSTEM: channel for system sounds
STREAM_VOICE_CALL: channel for voice calls

kotlin

// Set audio attributes
val player = MediaPlayer()
player.setAudioAttributes(
    AudioAttributes.Builder()
        .setUsage(AudioAttributes.USAGE_ASSISTANCE_ACCESSIBILITY)
        .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
        .setLegacyStreamType(AudioManager.STREAM_ACCESSIBILITY)
        .build()
)

// Provide media controls
button.setOnClickListener {
    if (player.isPlaying()) {
        player.pause()
    } else {
        player.start()
    }
}

In Jetpack Compose apps, you should always be able to control audio. When using MediaPlayer, you should implement buttons to call the start), pause) and stop) methods.

It is a best practice to play audio through the correct channel. Android has introduced AudioAttributes as a replacement of the STREAM types defined in AudioManager.

AudioAttributes defines the following content types:

CONTENT_TYPE_MOVIE: used for soundtracks, typically in movies
CONTENT_TYPE_MUSIC: used for music
CONTENT_TYPE_SONIFICATION: used for accompanying sounds, such as beeps
CONTENT_TYPE_SPEECH: used for speech
CONTENT_TYPE_UNKNOWN: used when the content type is unknown, or other than the available options

AudioAttributes defines the following usages:

USAGE_ALARM: used for alarms
USAGE_ASSISTANCE_ACCESSIBILITY: used for accessibility, e.g. for screen reader users
USAGE_ASSISTANCE_NAVIGATION_GUIDANCE: used for navigation directions, e.g. while driving
USAGE_ASSISTANCE_SONIFICATION: used for user interface sounds
USAGE_ASSISTANT: used for user queries, audio instructions or help utterances.
USAGE_GAME: used for audio inside games
USAGE_MEDIA: used for audio in media, such as movies
USAGE_NOTIFICATION: used for notification sounds
USAGE_NOTIFICATION_EVENT: used to attract the user's attention, such as a reminder or low battery warning.
USAGE_NOTIFICATION_RINGTONE: used for telephony ringtones
USAGE_UNKNOWN: used when the usage is unknown, or not defined
USAGE_VOICE_COMMUNICATION: used for voice communication, such as telephony or VoIP
USAGE_VOICE_COMMUNICATION_SIGNALLING: used for in-call signalling, such as with a "busy" beep, or DTMF tones.

kotlin

// Set audio attributes
val player = remember {
    MediaPlayer().apply {
        setAudioAttributes(
            AudioAttributes.Builder()
                .setUsage(AudioAttributes.USAGE_ASSISTANCE_ACCESSIBILITY)
                .setContentType(AudioAttributes.CONTENT_TYPE_SPEECH)
                .setLegacyStreamType(AudioManager.STREAM_ACCESSIBILITY)
                .build()
        )
    }
}
// Provide media controls
Button(
    onClick = {
        if (player.isPlaying) {
            player.pause()
        } else {
            player.start()
        }
    }
) {
    // Button content...
}

In iOS apps you should always be able to control audio. When using AVPlayer, you should use play and pause methods.

You should also make sure that audio is played through the correct channel. Use AVAudioSession in combination with AVAudioSessionCategory to achieve this.

The following channels are available:

AVAudioSessionCategoryAmbient: use this channel if the sound is not important for the functioning of the app
AVAudioSessionCategoryMultiRoute: use this channel if you are sending the sound to multiple output devices at the same time
AVAudioSessionCategoryPlayAndRecord: use this channel for sound recording and playback
AVAudioSessionCategoryPlayback: use this channel to play recorded music and other sounds that are important for the app's functioning
AVAudioSessionCategoryRecord: use this channel for sound recording; other sound is muted
AVAudioSessionCategorySoloAmbient: the default channel to play sound

swift

// Set audio channel
try AVAudioSession.sharedInstance().setCategory(
    .playback, 
    mode: .default, 
    options: []
)

// Provide media controls
@objc private func click(_ sender: UIButton) {
    if player.timeControlStatus == .playing {
        player.pause()
    } else {
        player.play()
    }
}

In SwiftUI apps you should always be able to control audio. When using AVPlayer, you should use play and pause methods.

You should also make sure that audio is played through the correct channel. Use AVAudioSession in combination with AVAudioSessionCategory to achieve this.

The following channels are available:

AVAudioSessionCategoryAmbient: use this channel if the sound is not important for the functioning of the app
AVAudioSessionCategoryMultiRoute: use this channel if you are sending the sound to multiple output devices at the same time
AVAudioSessionCategoryPlayAndRecord: use this channel for sound recording and playback
AVAudioSessionCategoryPlayback: use this channel to play recorded music and other sounds that are important for the app's functioning
AVAudioSessionCategoryRecord: use this channel for sound recording; other sound is muted
AVAudioSessionCategorySoloAmbient: the default channel to play sound

swift

// Set audio channel
try AVAudioSession.sharedInstance().setCategory(
    .playback, 
    mode: .default, 
    options: []
)

// Provide media controls
@State private var player = AVPlayer()
@State private var isPlaying = false

var body: some View {
    Button(isPlaying ? "Pause" : "Play") {
        if player.timeControlStatus == .playing {
            player.pause()
            isPlaying = false
        } else {
            player.play()
            isPlaying = true
        }
    }
}

In Flutter apps you should always be able to control audio. Two popular options for playing media are video_player and just_audio. Both packages have options for controlling audio through play() and pause() methods.

dart

final player = AudioPlayer();                   
final duration = await player.setUrl('https://appt.org/audio.mp3');

IconButton(
  icon: Icon(Icons.play_arrow),
  iconSize: 64.0,
  onPressed: await player.play(),
);

IconButton(
  icon: Icon(Icons.pause),
  iconSize: 64.0,
  onPressed: await player.pause(),
);

In React Native apps you should always be able to control audio. A popular option for media is the react-native-video package. You can use the audioOnly property to play audio files. The react-native-video package offers native controls for playing and pausing by default.

jsx

<Video 
    audioOnly
    post={require('appt.png')} 
    source={require('appt.mp3')} />

In MAUI apps you should be able to control audio. There is no built-in audio control, but you can use the MediaElement from the MAUI Community Toolkit, which surfaces the following native components:

Exoplayer, Android
AVPlayer, iOS

C# example

csharp

var mediaElement = new MediaElement
{
    ShouldAutoPlay = true,
    Source = "TheUrlOrPathForYouAudio.mp3"
};

xml

xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"
<toolkit:MediaElement 
    Source="TheUrlOrPathForYouAudio.mp3"
    ShouldAutoPlay="True" />

In Xamarin apps you should always be able to control audio. You can use MediaElement to embed media. The ShowsPlaybackControls needs to be set to True to show controls for playing and pausing. The value is False by default.

xml

<MediaElement Source="https://appt.org/video.mp4"
              ShowsPlaybackControls="True" />

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1.4.2 — Audio Control

Add audio control

Android

Jetpack Compose

iOS

SwiftUI

Flutter

React Native

.NET MAUI

Xamarin