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.

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.

EDIT: Since your question has also an edit: If you put a tube between the two friends, it is true you dont have a problem with sound volumen, but then you also dont have any of the effects you are looking for. This would be the same like sitting inside the airplane (since the air for communication is stationary between the two friend). Nothing weird happening inside a concorde.

Well, there is actually a lot of effort on your part (going mach 1 outside a plan is not easy). There are two bigger problems though. The intensity of the sound is decreasing with distance with 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.

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.