looping of sounds

I am trying to use Pushover to locate my Iphone if it is lost.  I just learned about critical alerts, which allow me to play a sound on the iphone even if it is in vibrate, which is awesome.  However, I would like to play a sound on loop until the phone is found.  There appears to be an option to do this in pushover but there is a long delay between playing of a sound.   Is there a way to just keep a sound going without delay between playing of the sound?