record-in-48khz-via-airpods.swift

// Thanks https://amorten.com/blog/2017/ios-bluetooth-and-microphone-input/

func configure() {
        // ...
        
        let session = AVAudioSession.sharedInstance()

        let sampleRate = 48000.0

        do {
            try session.setCategory(
                .playAndRecord, // Simultaneously play and record audio
                mode: .default, // .voiceChat somehow breaks with .allowBluetoothA2DP, making microphone not work
                options: [
                    .mixWithOthers, // Mix audio with other apps
                    .allowBluetoothA2DP, // Allow the use of Bluetooth devices like AirPods (DO NOT USE .allowBluetooth, which forces audio to 16kHz
                    .defaultToSpeaker,
                    .allowAirPlay,
                ]
            )

            try session.setPreferredSampleRate(sampleRate)

            print("Configured audio session: \(session.sampleRate)")
        } catch {
            print("Error configuring audio session: \(error)")
            return
        }
}

I've tried this but not working for my AirPods Pro. Playing audio route to AirPods is fine, but recording by AirPods is failed, still using iPhone builtin microphone.