Well, there is actually a lot of effort on your part (going mach 1 outside a plane is not easy). There are two bigger problems though. The intensity of the sound is decreasing with distance as 1/d^2. So when you 'hear' your friend it is like you trying to hear him when he is a few hundred metres away. Apart from trying to detect such a low signal, there is also a supersonic boom, making it even worse.