Inter-App Audio (IAA) is adeprecated^[1] technology developed byApple Inc. which routes audio andMIDI signals between applications on theiOSmobile operating system. The technology was first introduced in 2013 iniOS 7 and deprecated in 2019 with the release ofiOS 13.

Inter-App Audio is ahost-plugin technology. An IAAhost application connects to anode application to send and receive audio,MIDI, timeline information, and other signals.

Node applications can be of the following types:

• Instruments (can receiveMIDI signals and produce audio signals)
• Generators (can produce audio signals)
• Effects (can receive, transform and send back audio signals)

At the moment, audio signal routing is only possible with asampling rate of 44.1KHz.

Inter-App Audio was deprecated in 2019 with the release of iOS 13 in favor of the third version ofAudio Units.^[2]

• Audiobus
• Audio Units
• Ableton Link

• IAA Host Application List
• IAA Instrument Application List
• IAA Effect Application List
• Apple WWDC 2013: What's New in Core Audio for iOS

• IOS
• Music software plugin architectures