iOS, CPU keeps increasing upon playing new song - ios

Question

I am using AVPlayer to play music via Streaming URLs. Upon playing the first song the CPU is at about 3-4%, but each time a new song gets played the CPU will jump up and seem to get stacked on itself. Why is this happening? This is the code I am using to play music.
- (void)updateTime {
UIImage *pauseButtonImage = [UIImage imageNamed:#"Pause"];
float duration = CMTimeGetSeconds(self.player.currentItem.duration);
float current = CMTimeGetSeconds(self.player.currentTime);
self.durationProgressView.progress = (current/duration);
if (self.durationProgressView.progress == 0)
{
[self.playPauseButton setBackgroundImage:pauseButtonImage forState:UIControlStateNormal];
}
}
-(void)playCurrentArtist:(NSDictionary *)currentArtist
{
NSString *streamString = [currentArtist objectForKey:#"stream_url"];
NSString *urlString = [NSString stringWithFormat:#"%#?client_id=%#", streamString,CLIENT_ID];
NSURL *URLFromString = [NSURL URLWithString:urlString];
self.player = nil;
AVPlayer *playerWithURL = [[AVPlayer alloc]initWithURL:URLFromString];
self.player = playerWithURL;
[self.player play];
self.durationProgressView.hidden = NO;
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(itemDidFinishPlaying:) name:AVPlayerItemDidPlayToEndTimeNotification object:[self.player currentItem]];
self.timer = [NSTimer scheduledTimerWithTimeInterval:.05 target:self selector:#selector(updateTime) userInfo:nil repeats:YES];
}
-(void)itemDidFinishPlaying:(NSNotification *) notification {
//if there are no tracks in queue
if (![self.hostQueue count]) {
NSLog(#"nothing in queue upon song finishing");
[[NSNotificationCenter defaultCenter]removeObserver:self name:AVPlayerItemDidPlayToEndTimeNotification object:[self.player currentItem]];
[self.hostCurrentArtist removeAllObjects];
[self setCurrentArtistFromCurrentArtist:self.hostCurrentArtist];
NSArray *argsCurrentArray = #[self.hostCurrentArtist];
[self.socket emit:kCurrentArtistChange args:argsCurrentArray];
}
else {
[self playNextSongInQueue];
[self setCurrentArtistFromCurrentArtist:self.hostCurrentArtist];
};
}
-(void)playNextSongInQueue
{
if ([self.hostQueue count]) {
[self.audioPlayer stop];
[self.timer invalidate];
[[NSNotificationCenter defaultCenter]removeObserver:self name:AVPlayerItemDidPlayToEndTimeNotification object:[self.player currentItem]];
UIImage *pausedButtonImage = [UIImage imageNamed:#"Pause"];
//Rearange tracks and current songs and emit them to the sever.
NSDictionary *currentTrack = [self.hostQueue objectAtIndex:0];
self.hostCurrentArtist = [currentTrack mutableCopy];
[self.hostQueue removeObjectAtIndex:0];
[self.tableView reloadData];
[self playCurrentArtist:self.hostCurrentArtist];
[self.playPauseButton setBackgroundImage:pausedButtonImage forState:UIControlStateNormal];
self.audioPlayer.delegate = self;
self.durationProgressView.hidden = NO;
self.timer = [NSTimer scheduledTimerWithTimeInterval:.5 target:self selector:#selector(updateTime) userInfo:nil repeats:YES];
NSArray *argsWithQueue = #[self.hostQueue];
NSArray *arrayWithTrack = #[currentTrack];
[self setCurrentArtistFromCurrentArtist:self.hostCurrentArtist];
}
}