I am also attempting to get ambisonic audio playback working with AVFoundation / AVFAudio with the AVAudioEngine through an AVAudioEnvironmentNode. I believe I have gotten a .WAV PCM Ambisonics B_Format (4 Channel) audio file playing back properly as shown in the code below. However, rotating the listeners head via listenerAngularOrientation.yaw doesn't affect the ambisonic audio rotation. private let AmbiPlayerNode = AVAudioPlayerNode() func playAmbiAudio(){ guard let AmbiFileURL = Bundle.main.url(forResource: "crowdAmbiOut", withExtension: "wav") else{ print("read ambi failed") return } let file = try! AVAudioFile(forReading: AmbiFileURL) let layout = AVAudioChannelLayout(layoutTag: kAudioChannelLayoutTag_Ambisonic_B_Format) let format = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: 44100, interleaved: false, channelLayout: (layout)!) guard let buffer = AVAudioPCMBuffer(pcmFormat: format, frameCapacity: UInt32(file.length)) else { print("buffer failed") return } try! file.read(into: buffer) engine.attach(AmbiPlayerNode) engine.connect(AmbiPlayerNode, to: environment, format: file.processingFormat) AmbiPlayerNode.scheduleBuffer(buffer, at: nil, options: .loops, completionHandler: nil) AmbiPlayerNode.sourceMode = .ambienceBed AmbiPlayerNode.play() }

I haven't mastered the Apple Developer forums formatting. Here is a more readable link.