Your draft looks great! Here's a refined version with the iOS 17 comparison emphasized and slightly better flow:
Hi Apple Engineers and fellow developers,
I'm experiencing a critical regression with ShazamKit's background operation on iOS 18. ShazamKit's SHManagedSession stops identifying songs in the background after approximately 20 seconds on iOS 18, while the exact same code works perfectly on iOS 17.
The behavior is consistent: the app works perfectly in the foreground, but when backgrounded or device is locked, it initially works for about 20 seconds then stops identifying new songs. The microphone indicator remains active suggesting audio access is maintained, but ShazamKit doesn't send identified songs in the background until you open the app again. Detection immediately resumes when bringing the app to foreground.
My technical setup uses SHManagedSession for continuous matching with background modes properly configured in Info.plist including audio mode, and Background App Refresh enabled. I've tested this on physical devices running iOS 18.0 through 18.5 with the same results across all versions. The exact same code running on iOS 17 devices works flawlessly in the background.
To reproduce: initialize SHManagedSession and start matching, begin song identification in foreground, background the app or lock device, play different songs which are initially detected for about 20 seconds, then after the timeout period new songs are no longer identified until you bring the app to foreground.
This regression has impacted my production app as users who rely on continuous background music identification are experiencing a broken feature. I submitted this as Feedback ID FB15255903 last September with no solution so far.
I've created a minimal demo project that reproduces this issue: https://github.com/tfmart/ShazamKitBackground
Has anyone else experienced this ShazamKit background regression on iOS 18? Are there any known workarounds or alternative approaches? Given the time this issue has persisted, could we please get acknowledgment of this regression, expected timeline for a fix, or any recommended workarounds?
Testing environment is Xcode 16.0+ on iOS 18.0-18.5 across multiple physical device models.
Any guidance would be greatly appreciated.
Audio
RSS for tagDive into the technical aspects of audio on your device, including codecs, format support, and customization options.
Selecting any option will automatically load the page
Post
Replies
Boosts
Views
Activity
I am trying to stream audio from local filesystem.
For that, I am trying to use an AVAssetResourceLoaderDelegate for an AVURLAsset. However, Content-Length is not known at the start. To overcome this, I tried several methods:
Set content length as nil, in the AVAssetResourceLoadingContentInformationRequest
Set content length to -1, in the ContentInformationRequest
Both of these cause the AVPlayerItem to fail with an error.
I also tried setting Content-Length as INT_MAX, and setting a renewalDate = Date(timeIntervalSinceNow: 5). However, that seems to be buggy. Even after updating the Content-Length to the correct value (e.g. X bytes) and finishing that loading request, the resource loader keeps getting requests with requestedOffset = X with dataRequest.requestsAllDataToEndOfResource = true. These requests keep coming indefinitely, and as a result it seems that the next item in the queue does not get played. Also, .AVPlayerItemDidPlayToEndTime notification does not get called.
I wanted to check if this is an expected behavior or is there a bug in this implementation. Also, what is the recommended way to stream audio of unknown initial length from local file system?
Thanks!
Dear Sirs,
I’ve written a virtual audio driver based on AudioDriverKit and running as dext in my MacOS app. Sometimes when waking up from a sleep state the recording side of my driver extension seems to hang and I don’t see any calls to my io_operation callback. Then the recording app like a DAW seems to hang when trying to start a recording. This doesn’t happen after short sleep states or after a complete new start of my MacBook.
I already opened a case in Feedback-Assistant on 5th of May (FB17503622) which also includes a sysdiagnose and a ktrace but I didn't get any feedback so far. Meanwhile some of our customers are getting angry and I'd like to know if there's anything I could do to fix this problem on my side.
We’re not sure whether this worked in previous MacOS versions, we think we didn’t observe this before 15.3.1 but at least since 15.3.1. we’ve seen this problem.
Best regards,
Johannes
Hello,
I have a CarPlay Navigation app and utilize the AVSpeechSynthesizer to speak directions to a user. Everything works great on my CarPlay simulator as well as when plugged into my GMC truck. However, I found out yesterday that one of my users with a Ford truck the audio would cut in an out.
After much troubleshooting, I was able to replicate this on my own truck when using Bluetooth to connect to CarPlay. My user was also utilizing Bluetooth. Has anyone else experienced this? Is there a fix to the problem?
import SwiftUI
import AVFoundation
class TextToSpeechService: NSObject, ObservableObject, AVSpeechSynthesizerDelegate {
private var speechSynthesizer = AVSpeechSynthesizer()
static let shared = TextToSpeechService()
override init() {
super.init()
speechSynthesizer.delegate = self
}
func configureAudioSession() {
speechSynthesizer.delegate = self
do {
try AVAudioSession.sharedInstance().setCategory(.playback, mode: .voicePrompt, options: [.mixWithOthers, .allowBluetooth])
} catch {
print("Failed to set audio session category: \(error.localizedDescription)")
}
}
func speak(_ text: String) {
Task(priority: .high) {
let speechUtterance = AVSpeechUtterance(string: text)
speechUtterance.voice = AVSpeechSynthesisVoice(language: AVSpeechSynthesisVoice.currentLanguageCode())
try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation)
speechSynthesizer.speak(speechUtterance)
}
}
func speechSynthesizer(_ synthesizer: AVSpeechSynthesizer, didFinish utterance: AVSpeechUtterance) {
Task {
stopSpeech()
try AVAudioSession.sharedInstance().setActive(false)
}
}
func stopSpeech() {
speechSynthesizer.stopSpeaking(at: .immediate)
}
}
Hi team,
With regards to Call (Live) Translations on VOIP:
Is it possible to invoke live translations within the app? (without going into the Call System UI)
Is it possible to navigate users from app to Call System UI via an API? (and also invoking the new live translations directly)
Will Apple support more languages apart from the current ones? (Currently I see 4 supported languages)
Using the official SwiftTranscriptionSampleApp from WWDC 2025, speech transcription takes 14+ seconds from audio input to first result, making it unusable for real-time applications.
Environment
iOS: 26.0 Beta
Xcode: Beta 5
Device: iPhone 16 pro
Sample App: Official Apple SwiftTranscriptionSampleApp from WWDC 2025
Configuration Tested
Locale: en-US (properly allocated with AssetInventory.allocate(locale:)) and es-ES
Setup: All optimizations applied (preheating, high priority, model retention)
I started testing in my own app to replace SFSpeech API and include speech detection but after long fights with documentation (this part is quite terrible TBH) I tested the example (https://developer.apple.com/documentation/speech/bringing-advanced-speech-to-text-capabilities-to-your-app) and saw same results.
I added some logs to check the specific time:
🎙️ [20:30:41.532] ✅ Analyzer started successfully - ready to receive audio!
🎙️ [20:30:41.532] Listening for transcription results...
🎙️ [20:30:56.342] 🚀 FIRST TRANSCRIPTION RESULT after 14.810s: 'Hello' (isFinal: false)
Questions
Is this expected performance for iOS 26 Beta, because old SFSpeech is far faster?
Are there additional optimization steps for SpeechTranscriber?
Should we expect significant performance improvements in later betas?
After updating to iOS 18.5, we’ve observed that outgoing audio from our app intermittently stops being transmitted during VoIP calls using AVAudioSession configured with .playAndRecord and .voiceChat. The session is set active without errors, and interruptions are handled correctly, yet audio capture suddenly ceases mid-call. This was not observed in earlier iOS versions (≤ 18.4). We’d like to confirm if there have been any recent changes in AVAudioSession, CallKit, or related media handling that could affect audio input behavior during long-running calls.
func configureForVoIPCall() throws {
try setCategory(
.playAndRecord, mode: .voiceChat,
options: [.allowBluetooth, .allowBluetoothA2DP, .defaultToSpeaker])
try setActive(true)
}
I've got a problem with my app where I'm testing it on my own phone.
I'm using audio kit to generate tones as part of the app. Everything seems to work fine. Sounds start, Stop, etc. They play when the app is closed and when the phone is locked, so background is working.
However, I'm seeing an issue where, even when STOP is pressed and the application exited, if I get a notification such as a text message, the base tone for the app starts to play.
If I then open the app, check the Start/Stop button - it says start so that. hasnt' been activated. If I click Start, then a 2nd tone starts. This one stops with the Stop button. However the original tone that was set off by an incoming message carries on playing.
Until I go to the Open Apps View on the phone and slide the application upwards.
For the life of me, I can't figure out whats happening here.
I was testing audio playback from YouTube in Safari, and the sound was clipping heavily. At first, I thought it might be due to the poor quality of my small sound system. However, when I took a screenshot and the screenshot sound effect itself produced a loud clipping noise, it became clear that this is not a mechanical problem with my speakers, nor an issue specific to YouTube or Safari. This appears to be a system-wide audio issue in macOS Tahoe 26 - Beta 5.
Many Apple users own both Bluetooth earphones (AirPods) and traditional wired earphones. While Bluetooth audio provides freedom of movement, some users still prefer wired earphones for comfort, sound profile, or personal preference. However, plugging wired earphones directly into an iPhone can feel restrictive and inconvenient during daily use.
This proposal suggests a hybrid audio approach where wired earphones can be connected to a Bluetooth-enabled AirPods charging case (or a similar Apple-designed module), allowing users to enjoy wired earphones without a physical connection to the iPhone.
#Problem Statement
*Wired earphones offer consistent audio quality and zero latency
*Bluetooth earphones provide freedom from cables
*Users must currently choose one or the other
*Plugging wired earphones into an iPhone limits movement and can feel intrusive in daily scenarios (walking, commuting, working)
There is no native Apple solution that allows wired earphones to function wirelessly while maintaining Apple’s audio experience standards.
#Proposed Solution
Introduce a Wired-to-Wireless Audio Mode through the AirPods charging case or a dedicated Apple Bluetooth audio bridge.
How it works:
User plugs wired earphones into the AirPods case (or a future AirPods accessory port)
The case acts as a Bluetooth audio transmitter
Audio is streamed wirelessly from iPhone to the case
The case outputs audio to the wired earphones
#User experiences:
No cable connected to the iPhone
Familiar wired earphone sound
Freedom of movement similar to Bluetooth earbuds
User Experience (UX Flow)
Plug wired earphones into the AirPods case
iPhone automatically detects:
“Wired Earphones via AirPods Case”
Seamless pairing using existing AirPods framework
Audio controls, volume, and switching handled through iOS
No additional apps required
#Key Benefits
Combines wired sound reliability with wireless convenience
Reduces physical cable disturbance during use
Extends usefulness of existing wired earphones
Minimal learning curve for users
Fits naturally into Apple’s ecosystem and design philosophy
#Privacy & Performance Considerations
On-device audio processing only
No cloud involvement
Low-latency audio using Apple’s proprietary Bluetooth codecs
Power-efficient usage leveraging AirPods case battery
#Target Users
Users who prefer wired earphones but want wireless freedom
Commuters and walkers
Developers and professionals who multitask
Users sensitive to Bluetooth earbud fit or comfort
#Ecosystem Fit
Builds on existing AirPods pairing and audio stack
Aligns with Apple’s focus on seamless UX
Could be implemented via:
New AirPods hardware
Firmware update + accessory
Dedicated Apple audio bridge
Two issues:
No matter what I set in
try audioSession.setPreferredSampleRate(x)
the sample rate on both iOS and macOS is always 48000 when the output goes through the speaker, and 24000 when my Airpods connect to an iPhone/iPad.
Now, I'm checking the current output loudness to animate a 3D character, using
mixerNode.installTap(onBus: 0, bufferSize: y, format: nil) { [weak self] buffer, time in
Task { @MainActor in
// calculate rms and animate character accordingly
but any buffer size under 4800 is just ignored and the buffers I get are 4800 sized.
This is ok, when the sampleRate is currently 48000, as 10 samples per second lead to decent visual results.
But when AirPods connect, the samplerate is 24000, which means only 5 samples per second, so the character animation looks lame.
My AVAudioEngine setup is the following:
audioEngine.connect(playerNode, to: pitchShiftEffect, format: format)
audioEngine.connect(pitchShiftEffect, to: mixerNode, format: format)
audioEngine.connect(mixerNode, to: audioEngine.outputNode, format: nil)
Now, I'd be fine if the outputNode runs at whatever if it needs, as long as my tap would get at least 10 samples per second.
PS: Specifying my favorite format in the
let format = AVAudioFormat(standardFormatWithSampleRate: 48_000, channels: 2)!
mixerNode.installTap(onBus: 0, bufferSize: y, format: format)
doesn't change anything either
I have a simple AVAudioEngine graph as follows:
AVAudioPlayerNode -> AVAudioUnitEQ -> AVAudioUnitTimePitch -> AVAudioUnitReverb -> Main mixer node of AVAudioEngine.
I noticed that whenever I have AVAudioUnitTimePitch or AVAudioUnitVarispeed in the graph, I noticed a very distinct crackling/popping sound in my Airpods Pro 2 when starting up the engine and playing the AVAudioPlayerNode and unable to find the reason why this is happening. When I remove the node, the crackling completely goes away. How do I fix this problem since i need the user to be able to control the pitch and rate of the audio during playback.
import AVKit
@Observable @MainActor
class AudioEngineManager {
nonisolated private let engine = AVAudioEngine()
private let playerNode = AVAudioPlayerNode()
private let reverb = AVAudioUnitReverb()
private let pitch = AVAudioUnitTimePitch()
private let eq = AVAudioUnitEQ(numberOfBands: 10)
private var audioFile: AVAudioFile?
private var fadePlayPauseTask: Task<Void, Error>?
private var playPauseCurrentFadeTime: Double = 0
init() {
setupAudioEngine()
}
private func setupAudioEngine() {
guard let url = Bundle.main.url(forResource: "Song name goes here", withExtension: "mp3") else {
print("Audio file not found")
return
}
do {
audioFile = try AVAudioFile(forReading: url)
} catch {
print("Failed to load audio file: \(error)")
return
}
reverb.loadFactoryPreset(.mediumHall)
reverb.wetDryMix = 50
pitch.pitch = 0 // Increase pitch by 500 cents (5 semitones)
engine.attach(playerNode)
engine.attach(pitch)
engine.attach(reverb)
engine.attach(eq)
// Connect: player -> pitch -> reverb -> output
engine.connect(playerNode, to: eq, format: audioFile?.processingFormat)
engine.connect(eq, to: pitch, format: audioFile?.processingFormat)
engine.connect(pitch, to: reverb, format: audioFile?.processingFormat)
engine.connect(reverb, to: engine.mainMixerNode, format: audioFile?.processingFormat)
}
func prepare() {
guard let audioFile else { return }
playerNode.scheduleFile(audioFile, at: nil)
}
func play() {
DispatchQueue.global().async { [weak self] in
guard let self else { return }
engine.prepare()
try? engine.start()
DispatchQueue.main.async { [weak self] in
guard let self else { return }
playerNode.play()
fadePlayPauseTask?.cancel()
playPauseCurrentFadeTime = 0
fadePlayPauseTask = Task { [weak self] in
guard let self else { return }
while true {
let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: true)
// Ramp up volume until 1 is reached
if volume >= 1 { break }
engine.mainMixerNode.outputVolume = volume
try await Task.sleep(for: .milliseconds(10))
playPauseCurrentFadeTime += 0.01
}
engine.mainMixerNode.outputVolume = 1
}
}
}
}
func pause() {
fadePlayPauseTask?.cancel()
playPauseCurrentFadeTime = 0
fadePlayPauseTask = Task { [weak self] in
guard let self else { return }
while true {
let volume = updateVolume(for: playPauseCurrentFadeTime / 0.1, rising: false)
// Ramp down volume until 0 is reached
if volume <= 0 { break }
engine.mainMixerNode.outputVolume = volume
try await Task.sleep(for: .milliseconds(10))
playPauseCurrentFadeTime += 0.01
}
engine.mainMixerNode.outputVolume = 0
playerNode.pause()
// Shut down engine once ramp down completes
DispatchQueue.global().async { [weak self] in
guard let self else { return }
engine.pause()
}
}
}
private func updateVolume(for x: Double, rising: Bool) -> Float {
if rising {
// Fade in
return Float(pow(x, 2) * (3.0 - 2.0 * (x)))
} else {
// Fade out
return Float(1 - (pow(x, 2) * (3.0 - 2.0 * (x))))
}
}
func setPitch(_ value: Float) {
pitch.pitch = value
}
func setReverbMix(_ value: Float) {
reverb.wetDryMix = value
}
}
struct ContentView: View {
@State private var audioManager = AudioEngineManager()
@State private var pitch: Float = 0
@State private var reverb: Float = 0
var body: some View {
VStack(spacing: 20) {
Text("🎵 Audio Player with Reverb & Pitch")
.font(.title2)
HStack {
Button("Prepare") {
audioManager.prepare()
}
Button("Play") {
audioManager.play()
}
.padding()
.background(Color.green)
.foregroundColor(.white)
.cornerRadius(10)
Button("Pause") {
audioManager.pause()
}
.padding()
.background(Color.red)
.foregroundColor(.white)
.cornerRadius(10)
}
VStack {
Text("Pitch: \(Int(pitch)) cents")
Slider(value: $pitch, in: -2400...2400, step: 100) { _ in
audioManager.setPitch(pitch)
}
}
VStack {
Text("Reverb Mix: \(Int(reverb))%")
Slider(value: $reverb, in: 0...100, step: 1) { _ in
audioManager.setReverbMix(reverb)
}
}
}
.padding()
}
}
I'm experiencing a significant limitation with MusicKit's Dolby Atmos implementation on macOS and would appreciate clarification on whether this is intended behavior or if there are solutions available.
When streaming Dolby Atmos content through MusicKit's ApplicationMusicPlayer, the output is limited to 2-channel stereo, even when:
Audio MIDI Setup is configured for 7.1.4 (12-channel) output
The same tracks play in full multichannel through the native Apple Music app
Dolby Atmos is set to "Automatic" in Apple Music preferences
Please let me know if there is anyway to enable this. If not, is this documented anywhere? Thanks!
Hi there!
We have a suite of AudioUnit v2 plugins that have been shipped for some time as aufx plugins, and we are looking into MIDI-related platform upgrades, so we need a way to update these plugins to request MIDI from Logic (and other AU hosts) but avoid changing our AU type and subtype so we don't break existing sessions. Any ideas on how we can do this?
I ran 5.1 audio tests in both YouTube and Apple Music, and I noticed that when sound is supposed to play from the rear or front surround speakers, it’s also duplicated in the front left and right channels. I’m absolutely sure the issue is with the Apple TV, because I played the same video directly through my TV’s native system, and the channel separation was correct.
Everything used to work perfectly before, so this must be a software issue. I’m currently on tvOS 26 Developer Beta 5, but I’m certain the problem also existed on the stable tvOS 18.5.
I’ve already reset and updated my Apple TV, and I also tried switching the audio format to forced Dolby Atmos 5.1. On the forums, I mostly see complaints about Dolby Atmos not working at all — in my case, everything technically works, but not the way it’s supposed to.
Topic:
Media Technologies
SubTopic:
Audio
My workout watch app supports audio playback during exercise sessions.
When users carry both Apple Watch, iPhone, and AirPods, with AirPods connected to the iPhone, I want to route audio from Apple Watch to AirPods for playback. I've implemented this functionality using the following code.
try? session.setCategory(.playback, mode: .default, policy: .longFormAudio, options: [])
try await session.activate()
When users are playing music on iPhone and trigger my code in the watch app, Apple Watch correctly guides users to select
AirPods, pauses the iPhone's music, and plays my audio.
However, when playback finishes and I end the session using the code below:
try session.setActive(false, options:[.notifyOthersOnDeactivation])
the iPhone
doesn't automatically resume the previously interrupted music playback—it requires manual intervention.
Is this expected behavior, or am I missing other important steps in my code?
Hello,
I am wondering if it is possible to have audio from my AirPods be sent to my speech to text service and at the same time have the built in mic audio input be sent to recording a video?
I ask because I want my users to be able to say "CAPTURE" and I start recording a video (with audio from the built in mic) and then when the user says "STOP" I stop the recording.
Hello! I'm use AVFoundation for preview video and audio from selected device, and I try use AVAudioEngine for preview audio in real-time, but I can't or I don't understand how select input device? I can hear only my microphone in real-time
So far, I'm using AVCaptureAudioPreviewOutput for in real-time hear audio, but I think has delay.
On iOS works easy with AVAudioEngine, but on macOS bruh...
Topic:
Media Technologies
SubTopic:
Audio
Tags:
AudioToolbox
AVAudioSession
AVAudioEngine
AVFoundation
Hello,
I’m new here. I'm developing an iOS app and I’d like to know whether it is possible to detect if a phone call is being recorded by another app running in the background.
I’ve already reviewed the documentation for CallKit and AVAudioSession, but I couldn’t find anything related. My expectation was that iOS might provide some callback or API to indicate if a call is being recorded (third-party apps), but so far I haven’t found a way.
My questions are:
Does iOS expose any API to detect if a call is being recorded?
If not, is there any indirect, Apple's policy compliant method (e.g., microphone usage events) that can be relied upon?
Or is this something that iOS explicitly prevents for privacyreasons?
Expecting solutions that align with Apple’s policies and would be accepted under the App Store Review Guidelines.
Thanks in advance for any guidance.
Hi everyone,
I'm running into an issue with AVAudioRecorder when handling interruptions such as phone calls or alarms.
Problem:
When the app is recording audio and an interruption occurs:
I handle the interruption with audioRecorder?.pause() inside AVAudioSession.interruptionNotification (on .began).
On .ended, I check for .shouldResume and call audioRecorder?.record() again.
The recorder resumes successfully, but only the audio recorded after the interruption is saved. The audio recorded before the interruption is lost, even though I'm using the same file URL and not recreating the recorder.
Repro:
Start a recording with AVAudioRecorder
Simulate a system interruption (e.g., incoming call)
Resume recording after the interruption
Stop and inspect the output audio file
Expected: Full audio (before and after interruption) should be saved.
Actual: Only the audio after interruption is saved; the earlier part is missing
Notes:
According to the documentation, calling .record() after .pause() should resume recording into the same file.
I confirmed that the file URL does not change, and I do not recreate the recorder instance.
No error is thrown by the system during this process.
This behavior happens consistently when the app is interrupted and resumed.
Question:
Is this a known issue? Is there a recommended workaround for preserving the full recording when interruptions happen?
Thanks in advance!