The Audio Source needs to be set up to play 3D positional sounds. The first parameter we want to change is Spatial Blend, and setting this value to 1 will ensure that the audio source will be fully positional. After you have done this, open the 3D Sound Settings subpanel by clicking the small horizontal arrow before the text.
You should see the 3D Sound Settings panel:
- Doppler Level: This is how audible the Doppler effect is. When it is zero, it is turned off. 1 means it should be quite audible for fast-moving objects.
- Spread: This sets the spread angle to 3D stereo or multichannel sound in the speaker space.
- Volume Rolloff: This describes how the sound will decrease its volume gradually with the distance
from the Audio Listener and Min Distance and Max Distance adjusting the values of the curves for us. Its possible values are:
- Logarithmic: Use this mode when you want a real-world rolloff
- Linear: Use this mode when you want to lower the volume of your sound over the distance
- Custom: Use this when you want to use a custom rolloff
Visit: https://docs.unity3d.com/Manual/class-AudioSource.html, for additional information about the Audio Source component.