How can I play a custom sound in WatchOS 3 that will playback on the watch speakers - audio

Question

I've read that we can now play custom sounds on the apple watch in watchos 3.
According to the announcement from Apple so apparently there is but I don't have an example to test it out: 3D spatial audio implemented using SCNAudioSource or SCNAudioPlayer. Instead, use playAudioSource:waitForCompletion: or the WatchKit sound or haptic APIs. Found here: https://developer.apple.com/library/prerelease/content/releasenotes/General/WhatsNewInwatchOS/Articles/watchOS3.html
Can someone place a simple example of this. I'm not using SceneKit in my app as I don't need it but if that's the only way to play a custom sound then I'd like to know the minimum code required to accomplish this. Preferably in Objective c but I'll take it in whatever shape. I'm ok using SpriteKit if that's easier also.
Here's what I have so far but it doesn't work:
SCNNode * audioNode = [[SCNNode alloc] init];
SCNAudioSource * audioSource = [SCNAudioSource audioSourceNamed:#"mysound.mp3"];
SCNAudioPlayer * audioPlayer = [SCNAudioPlayer audioPlayerWithSource:audioSource];
[audioNode addAudioPlayer:audioPlayer];
SCNAction * play = [SCNAction playAudioSource:audioSource waitForCompletion:YES];
[audioNode runAction:play];

Answer 1

I can confirm, that #ApperleyA solution really works!
Here is the swift version:
var _audioPlayer : AVAudioPlayerNode!
var _audioEngine : AVAudioEngine!
func playAudio()
{
if (_audioPlayer==nil) {
_audioPlayer = AVAudioPlayerNode()
_audioEngine = AVAudioEngine()
_audioEngine.attach(_audioPlayer)
let stereoFormat = AVAudioFormat(standardFormatWithSampleRate: 44100, channels: 2)
_audioEngine.connect(_audioPlayer, to: _audioEngine.mainMixerNode, format: stereoFormat)
do {
if !_audioEngine.isRunning {
try _audioEngine.start()
}
} catch {}
}
if let path = Bundle.main.path(forResource: "test", ofType: "mp3") {
let fileUrl = URL(fileURLWithPath: path)
do {
let asset = try AVAudioFile(forReading: fileUrl)
_audioPlayer.scheduleFile(asset, at: nil, completionHandler: nil)
_audioPlayer.play()
} catch {
print ("asset error")
}
}
}

Answer 2

This is Objective-c but can be translated into Swift
I ended up using AVAudioEngine and AVAudioPlayerNode to play audio on the Apple watch.
The gist of how to do this is as follows:
I call the following inside the init method of my AudioPlayer (it's an NSObject subclass to encapsulate the functionality)
_audioPlayer = [[AVAudioPlayerNode alloc] init];
_audioEngine = [[AVAudioEngine alloc] init];
[_audioEngine attachNode:_audioPlayer];
AVAudioFormat *stereoFormat = [[AVAudioFormat alloc] initStandardFormatWithSampleRate:44100 channels:2];
[_audioEngine connect:_audioPlayer to:_audioEngine.mainMixerNode format:stereoFormat];
if (!_audioEngine.isRunning) {
NSError* error;
[_audioEngine startAndReturnError:&error];
}
I have a cache setup so I don't recreate the AVAudioFile assets every time I want to play a sound but you don't need to.
So next create an AVAudioFile object:
NSError *error;
NSBundle* appBundle = [NSBundle mainBundle];
NSURL *url = [NSURL fileURLWithPath:[appBundle pathForResource:key ofType:#"aifc"]];
AVAudioFile *asset = [[AVAudioFile alloc] initForReading:url &error];
Then play that file:
[_audioPlayer scheduleFile:asset atTime:nil completionHandler:nil];
[_audioPlayer play];
UPDATE: If the app goes to sleep or is put to the background there is a chance the audio will stop playing/fade out. By activating an Audio Session this will be prevented.
NSError *error;
[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:&error];
if (error) {
NSLog(#"AVAudioSession setCategory ERROR: %#", error.localizedDescription);
}
[[AVAudioSession sharedInstance] setActive:YES error:&error];
if (error) {
NSLog(#"AVAudioSession setActive ERROR: %#", error.localizedDescription);
}
I didn't go over handling any errors but this should work. Don't forget to #import <AVFoundation/AVFoundation.h> at the top of your implementation file.

Answer 3

This worked for me in the simulator
let soundPath = Bundle.main.path(forResource: "cheerMP3", ofType: "mp3")
let soundPathURL = URL(fileURLWithPath: soundPath!)
let audioFile = WKAudioFileAsset(url: soundPathURL)
let audioItem = WKAudioFilePlayerItem(asset: audioFile)
let audioPlayer = WKAudioFilePlayer.init(playerItem: audioItem)
if audioPlayer.status == .readyToPlay
{
audioPlayer.play()
}
else
{
print("Not ready!!")
}
but only if I had a breakpoint at both audioPlayer.play() and after the last }.
dunqan, what did you put at the top of the file, the import statements? I wasn't able to include
import AVFoundation
without an error using Xcode 8.2.1