[EthanR]

Код:

if(IsPlayerInRangeOfPoint(playerid, putradiushere, coordx, coordy, coordz) && AudioStreamOn[playerid] == 0) 
{
	PlayAudioStreamForPlayer(playerid, "audiostreamurlhere");
	AudioStreamOn[playerid] = 1;			
}

// This somewhere into your gamemode.

new AudioStreamOn[MAX_PLAYERS];


and something like AudioStreamOn[playerid] = 0; OnPlayerConnect, to reset the value for joining players.



EDIT: You should put the InRange check into a 1-2 second timer, OnPlayerUpdate isn't really needed here. (OnPlayerInteriorChange might be good though)