The prediction gain of audio codecs is <1, which basically means that if you start at a random packet, once you play enough packets it'll converge to sound the

The prediction gain of audio codecs is <1, which basically means that if you start at a random packet, once you play enough packets it'll converge to sound the same as if you had started playing from the beginning. It'll sound bad at the beginning though, so you usually crop off the first bit after seeking (80ms for Opus, much longer for other codecs). Another source of delay is just the length of audio packets themselves (have to wait for the beginning of one) and radio limitations.