how to sync audio in iphone sdk with NStimer?

I am running a countdown timer which updates time on a label.i want to play a tick sound every second.i have the sound file but it is not sync perfectly with time.how do i sync time with audio?also if i use uiimagepicker the sound stops how to manage this? if someone have tick sound like a clock has it would开发者_运维问答 be great.

The best way to sync up your sound and time would be to actually play short - less than a second long - sound files (tick sound) once per second as TSTimer fires. It won't sound as nice as a real clock or chronometer ticking, but it would be easy to do. And if the sounds are that small, then you don't have to worry too much about latency. I think to be realistic you need to play two ticks per second, with the first and second ticks about 0.3 seconds apart, and the next one starting at the next second, with the fourth, again only about 0.3 seconds later. And so on.

For even tighter integration of sounds and GUI, you should read up on Audio Toolbox:

Use the Audio Toolbox framework to play audio with synchronization capabilities, access packets of incoming audio, parse audio streams, convert audio formats, and record audio with access to individual packets. For details, see Audio Toolbox Framework Reference and the SpeakHere sample code project.