How to calculate the sound volume for the left ear and right ear based on the object position & velocity, player position & forward vector? (3D sound) [closed]

Question

Please assume:

Minimum distance for 3D volume = 1.0;
Maximum distance for 3D volume = 100.0;

This is the declaration of the function:

An object can be a ball moving closer to the player.

void CalculateSoundVolume(Vec3 objectPosition, 
                          Vec3 objectVelocity, 
                          Vec3 userHead, 
                          Vec3 userFoward, 
                          float& leftEarVolume, 
                          float& rightEarVolume)  
{

}