Collision magnitude based on angle and velocity

Hi all,

I am creating a golf like game and want to play a sound when the ball hits a wall or floor etc..

I can get the relativemagnitude of the collision to alter the sound clip volume but this just means that when I clip a wall travelling fast it plays a loud sound.

What I want is a relativemagnitude based on normals, at least I think I do. So if the ball is hit nearly vertically up but fast and brushes an object it doesn't make the loudest sound.

Is there a way to do this I have searched for ages and keep coming up blank.

Thanks in advance people.

Mike