I found the problem. 1: Because the recording operation needs to press the Bluetooth button and hold it all the time to start recording. Let go and stop recording. 2: When you press and hold the Bluetooth device button. The mobile phone will always receive the data sent by the Bluetooth device. The recorded audio at this time is noise (the app is always running in the background). 3: But it is normal that there is no noise when the app is running in the foreground and repeats the recording operation. 4: Press and lift the Bluetooth device button to start recording. Wait for the recording. Press and lift again. Stop recording. At this time, the recording is normal and there is no noise. 5: So how to do it without changing the audio session mode when long pressing (long press will always receive the data sent by Bluetooth) 6: How to maintain the audio mode at the beginning

1: Turn on the PushToTalk status 2: The application switches to the background 3: Use a Bluetooth device to call up the microphone for audio recording and write the audio data to the file Can you help me write the relevant code? ( I spent more than a month on this function, but it hasn't been solved) Thank you.

https://qiniuyun.hanshengw.top/%E6%BC%94%E7%A4%BA4.mp4

PTTManager This is my PTT code 1: Click on the intercom button and Bluetooth device button on the PushToTalk interface. The recording all starts in this method (channelManager: PTChannelManager, didActivate AudioSession: AVAudioSession) 2: There is no problem with recording audio by clicking the intercom button on the PushToTalk interface. But there are problems with clicking on recorded audio on Bluetooth devices (all noise or no sound during playback) 3: The method called after the application switches to the background (setupChannelManager (channelUUID: UUID)) 4: The method called by clicking the Bluetooth button (requestBeginTransmitting()) 5: The above scenarios are all when the application switches to the background (the application has set the background to keep alive and Background Modes) 6: All functions are normal without any issues when the application switches to the frontend.

https://ss.bscstorage.com/playlet-oss-res/video/2025195/%E6%BC%94%E7%A4%BA3.mp4?AWSAccessKeyId=6jndo5gcx079kvpu3myf&Expires=1760941761&Signature=hBcY7TDq%2BZHOARoFKY6CAthju%2Fc%3D This is the link of the demonstration video. How is this function effect in the video achieved?

The “Zello Walkie Talkie” app's intercom function is perfectly implemented

Firstly, I am using AVAudioEngine for recording implementation. We are not currently using CallKit. The audio recorded by AVAudioEngine still has noise in the above scenario (when PushToTalk is turned on and the app is switched to the background, the app is in a state of long-term survival in the background, and then AVAudioEngine recording is started by clicking the Bluetooth device button), but I found that the audio recorded after clicking the intercom button on the PushToTalk interface has no noise. The audio recorded by clicking the Bluetooth device button is noise. The method called by Bluetooth devices is (requestBeginTransmitting), which enables AVAudioEngine recording in the (channelManager: PTChannelManager, didActivate audioSession: AVAudioSession) method. Is there any additional setting for the intercom button on the PushToTalk interface?

In the above scenario, the sound recorded with AVAudioRecorder is all noise.

{ 　　"aps" : { "alert" : "You got your emails.", "badge" : 1, "sound" : "default" }, "rc":{ "cType":"PR", "fId":"2121", "oName":"RC:TxtMsg", "tId":"3232", "rId":"3243", "id":"5FSClm2gQ9V9BZ-kUZn58B", "rc-dlt-identifier":"2FSClm2gQ" }, "appData":"https://chushuo.com/sdhkguawggcguauw.mp3" } When the app is not running, as long as it receives APNS remote push. How to play the voice of 'appData'. Users do not require any additional actions