Set the Voice Effect

Introduction

In social and entertainment scenarios, users often want various voice effects to improve their interactive experiences. For example, in chat rooms, a user can select a voice effect to add a virtual stereo effect to their voice.

To accomplish this, Agora RTC SDK provides preset voice effects. You can also dynamically change the users' voices, such as adjusting the pitch, setting the equalization, and reverberation modes. Try out the preset voice effects on the online Demo provided by Agora.

Sample project

Agora provides the following open-source sample projects that implement the voice beautifier and audio effects functions on GitHub. You can download them to try out this function and view the source code.

• iOS: VoiceChanger
• macOS: VoiceChanger

Use preset voice effects

To meet the requirements for voice effects in different scenarios, Agora provides setVoiceBeautifierPreset and setAudioEffectPreset. You can use the following SDK preset voice effects:

Chat beautifier

Chat beautifier refers to beautifying the characteristics of male or female voices without altering the original voice beyond recognition.

You can implement the chat beautifier by the enumerations in setVoiceBeautifierPreset as follows:

// Swift 
// Beautifies the local voice by making it sound more magnetic (for male only).
agoraKit.setVoiceBeautifierPreset(.chatBeautifierMagnetic)
// Disables voice effects.
agoraKit.setVoiceBeautifierPreset(.voiceBeautifierOff)

// Objective-C
// Beautifies the local voice by making it sound more magnetic (for male only).
[self.agoraKit setVoiceBeautifierPreset: AgoraChatBeautifierMagnetic];
// Disables voice effects.
[self.agoraKit setVoiceBeautifierPreset: AgoraVoiceBeautifierOff];

Singing beautifier

Singing beautifier refers to beautifying male or female singing voices without greatly altering their original characteristics, as well as adding a reverberation effect.

You can implement the singing beautifier by the enumeration AgoraSingingBeautifier.

• If you call setVoiceBeautifierPreset(AgoraSingingBeautifier), you can beautify a male-sounding voice and add a reverberation effect that sounds like singing in a small room. Agora recommends not using setVoiceBeautifierPreset(AgoraSingingBeautifier) to process a female-sounding voice; otherwise, you may experience vocal distortion.
• If you call setVoiceBeautifierParameters(AgoraSingingBeautifier, param1, param2), you can beautify a male- or female-sounding voice and add one of several reverberation effects.

// Swift  
// Beautifies the singing voice of the local user.   
agoraKit.setVoiceBeautifierPreset(.singingBeautifier)   
// Beautifies a female-sounding voice and add a reverberation effect that sounds like singing in a hall.  
agoraKit.setVoiceBeautifierParameters(.singingBeautifier, 2, 3)   
// Disables voice effects.  
agoraKit.setVoiceBeautifierPreset(.voiceBeautifierOff)

// Objective-C  
// Beautifies the singing voice of the local user.  
[self.agoraKit setVoiceBeautifierPreset: AgoraSingingBeautifier];   
// Beautifies a female-sounding voice and add a reverberation effect that sounds like singing in a hall.  
[self.agoraKit setVoiceBeautifierParameters: AgoraSingingBeautifier param1:2 param2:3];   
// Disables voice effects.  
[self.agoraKit setVoiceBeautifierPreset: AgoraVoiceBeautifierOff];

Timbre transformation

Timbre transformation changes the timbre of a voice in a specific way. Users can choose the most appropriate effect for their voice.

You can implement the timbre transformation by the enumerations in setVoiceBeautifierPreset as follows:

// Swift 
// Beautifies the local voice by making it sound more vigorous.
agoraKit.setVoiceBeautifierPreset(.timbreTransformationVigorous)
// Disables voice effects.
agoraKit.setVoiceBeautifierPreset(.voiceBeautifierOff)

// Objective-C
// Beautifies the local voice by making it sound more vigorous.
[self.agoraKit setVoiceBeautifierPreset: AgoraTimbreTransformationVigorous];
// Disables voice effects.
[self.agoraKit setVoiceBeautifierPreset: AgoraVoiceBeautifierOff];

Voice changer

Voice changer changes the original voice mainly for fun effects. This effect makes the original voice less natural, so that listeners can tell that the voice has been changed.

You can implement the voice changer effect by the enumerations in setAudioEffectPreset as follows:

// Swift 
// Presets the local voice by making it sound like the Hulk.
agoraKit.setAudioEffectPreset(.voiceChangerEffectHulk)
// Disables voice effects.
agoraKit.setAudioEffectPreset(.audioEffectOff)

// Objective-C
// Presets the local voice by making it sound like the Hulk.
[self.agoraKit setAudioEffectPreset: AgoraVoiceChangerEffectHulk];
// Disables voice effects.
[self.agoraKit setAudioEffectPreset: AgoraAudioEffectOff];

Style transformation

A style transformation makes singing more harmonious for specific styles of songs.

You can implement the style transformation by the enumerations in setAudioEffectPreset as follows:

// Swift 
// Presets the local voice to the style of pop music.
agoraKit.setAudioEffectPreset(.styleTransformationPopular)
// Disables voice effects.
agoraKit.setAudioEffectPreset(.audioEffectOff)

// Objective-C
// Presets the local voice to the style of pop music.
[self.agoraKit setAudioEffectPreset: AgoraStyleTransformationPopular];
// Disables voice effects.
[self.agoraKit setAudioEffectPreset: AgoraAudioEffectOff];

Room acoustics

Room acoustics refers to the spatial dimension added to a user’s voice for making the voice seem to come from a specific type of enclosed place.

You can implement the space construction by the enumerations in setAudioEffectPreset as follows:

// Swift 
// Presets the local voice by making it appear to be moving around the user.
agoraKit.setAudioEffectPreset(.roomAcoustics3DVoice)
// Changes the cycle period to 30 seconds.
agoraKit.setAudioEffectParameters(.roomAcoustics3DVoice, 30, 0)
// Disables voice effects.
agoraKit.setAudioEffectPreset(.audioEffectOff)

// Objective-C
// Presets the local voice by making it appear to be moving around the user.
[self.agoraKit setAudioEffectPreset: AgoraRoomAcoustics3DVoice];
// Changes the cycle period to 30 seconds.
[self.agoraKit setAudioEffectParameters: AgoraRoomAcoustics3DVoice param1:30 param2:0];
// Disables voice effects.
[self.agoraKit setAudioEffectPreset: AgoraAudioEffectOff];

Pitch correction

Pitch correction refers to the effect for correcting a singing voice to make it match the song based on the basic mode and the tonic pitch.

You can implement the pitch correction by the enumerations in setAudioEffectPreset as follows:

// Swift 
// Presets the local voice by making it match the song.
agoraKit.setAudioEffectPreset(.pitchCorrection)
// Changes the basic mode to natural minor scale and the tonic pitch to D.
agoraKit.setAudioEffectParameters(.pitchCorrection, 2, 6)
// Disables voice effects.
agoraKit.setAudioEffectPreset(.audioEffectOff)

// Objective-C
// Presets the local voice by making it match the song.
[self.agoraKit setAudioEffectPreset: AgoraPitchCorrection];
// Changes the basic mode to natural minor scale and the tonic pitch to D.
[self.agoraKit setAudioEffectParameters: AgoraPitchCorrection param1:2 param2:6];
// Disables voice effects.
[self.agoraKit setAudioEffectPreset: AgoraAudioEffectOff];

Voice conversion

Voice conversion naturally changes the original voice mainly for anonymous effects. Listeners cannot tell that the voice has been changed without listening to the original voice.

You can implement the voice changer by the enumerations in setVoiceConversionPreset as follows:

// Swift  
// Presets the local voice by making it sound like a gender-neutral voice. 
preset = VOICE_CHANGER_NEUTRAL; 
agoraKit.setVoiceConversionPreset(.voiceChangerNeutral)  
// Disables voice effects. 
agoraKit.setVoiceConversionPreset(.voiceConversionOff)

// Objective-C  
// Presets the local voice by making it sound like a gender-neutral voice. 
preset = VOICE_CHANGER_NEUTRAL; 
[self.agoraKit setVoiceConversionPreset: AgoraVoiceChangerNeutral];  
// Disables voice effects. 
[self.agoraKit setVoiceConversionPreset: AgoraVoiceConversionOff];

Customize voice effects

If the preset effect does not meet your requirement, you can also customize the voice effects by adjusting the voice pitch, equalization, and reverberation settings through setLocalVoicePitch, setLocalVoiceEqualization, and setLocalVoiceReverb.

The following sample code shows how to change the original user's voice to the Hulk's voice.

// Swift 
// Sets the pitch. The value ranges between 0.5 and 2.0. The lower the value, the lower the pitch. The default value is 1.0, which is the original pitch.
agoraKit.setLocalVoicePitch(1)

// Sets the local voice equalization.
// The first parameter sets the band frequency. The value ranges between 0 and 9. Each value represents the center frequency of the band: 31, 62, 125, 250, 500, 1k, 2k, 4k, 8k, and 16k Hz.
// The second parameter sets the gain of each band. The value ranges between -15 and 15 dB. The default value is 0.
agoraKit.setLocalVoiceEqualizationOf(.band31, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band62, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band125, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band250, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band500, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band1K, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band2K, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band4K, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band8K, withGain: 0)
agoraKit.setLocalVoiceEqualizationOf(.band16K, withGain: 0)

// The level of the dry signal in dB. The value ranges between -20 and 10.
agoraKit.setLocalVoiceReverbOf(.dryLevel, withValue: -1)

// The level of the early reflection signal (wet signal) in dB. The value ranges between -20 and 10.
agoraKit.setLocalVoiceReverbOf(.wetLevel, withValue: -7)

// The room size of the reverberation. A larger room size means a stronger reverberation. The value ranges between 0 and 100.
agoraKit.setLocalVoiceReverbOf(.roomSize, withValue: 57)

// The length of the initial delay of the wet signal (ms). The value ranges between 0 and 200.
agoraKit.setLocalVoiceReverbOf(.wetDelay, withValue: 135)

// The reverberation strength. The value ranges between 0 and 100. The higher the value, the stronger the reverberation.
agoraKit.setLocalVoiceReverbOf(.strength, withValue: 45)

// Objective-C
// Sets the pitch. The value ranges between 0.5 and 2.0. The lower the value, the lower the pitch. The default value is 1.0, which is the original pitch.
[agoraKit setLocalVoicePitch: 1];

// Sets the local voice equalization.
// The first parameter sets the band frequency. The value ranges between 0 and 9. Each value represents the center frequency of the band: 31, 62, 125, 250, 500, 1k, 2k, 4k, 8k, and 16k Hz.
// The second parameter sets the gain of each band. The value ranges between -15 and 15 dB. The default value is 0.
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand31 withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand62 withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand125 withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand250 withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand500 withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand1K withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand2K withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand4K withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand8K withGain: 0];
[agoraKit setLocalVoiceEqualizationOfBandFrequency:AgoraAudioEqualizationBand16K withGain: 0];

// The level of the dry signal in dB. The value ranges between -20 and 10.
[agoraKit setLocalVoiceReverbOfType:AgoraAudioReverbDryLevel withValue: -1];

// The level of the early reflection signal (wet signal) in dB. The value ranges between -20 and 10.
[agoraKit setLocalVoiceReverbOfType:AgoraAudioReverbWetLevel withValue: -7];

// The room size of the reverberation. A larger room size means a stronger reverberation. The value ranges between 0 and 100.
[agoraKit setLocalVoiceReverbOfType:AgoraAudioReverbRoomSize withValue: 57];

// The length of the initial delay of the wet signal (ms). The value ranges between 0 and 200.
[agoraKit setLocalVoiceReverbOfType:AgoraAudioReverbWetDelay withValue: 135];

// The reverberation strength. The value ranges between 0 and 100. The higher the value, the stronger the reverberation.
[agoraKit setLocalVoiceReverbOfType:AgoraAudioReverbStrength withValue: 45];

API reference

Preset voice effects

• setAudioEffectPreset
• setVoiceBeautifierPreset
• setAudioEffectParameters
• setVoiceBeautifierParameters
• setVoiceConversionPreset

Customized voice effects

• setLocalVoicePitch
• setLocalVoiceEqualizationOfBandFrequency
• setLocalVoiceReverbOfType

Considerations

• Do not set the profile parameter of setAudioProfile to AgoraAudioProfileSpeechStandard(1); otherwise, the following methods do not take effect.
  • setAudioEffectPreset
  • setVoiceBeautifierPreset
  • setAudioEffectParameters
  • setVoiceBeautifierParameters
  • setVoiceConversionPreset
• All methods mentioned in this article work best with the human voice. Agora does not recommend using them for audio containing both music and voice.
• Agora recommends not calling the following methods together, because the method called subsequently overrides whichever one is called before it:
  • setAudioEffectPreset
  • setVoiceBeautifierPreset
  • setAudioEffectParameters
  • setVoiceBeautifierParameters
  • setVoiceConversionPreset
  • setLocalVoicePitch
  • setLocalVoiceEqualizationOfBandFrequency
  • setLocalVoiceReverbOfType