Why some audio sounds are not hearable if "3D Sound" is checked ?

I recorded a sound that I want to be played in my Unity scene but I’m not able to hear it. Only a little noise is produced even if the camera audio listener if near the audio source.
Note that I don’t have this issue with all my recorded sounds, only some of them.

Also note that if I uncheck “3D Sound” in the asset inspector, the sound is perfectly hearable like if it was played with VLC.

Why this is happening?

Please download and test it: [25269-unlock.zip|25269]

The actual volume arriving at your speakers depends on the distance between the 3D sound audio source and the audio listener. In the 3D sound settings of the audio source you can setup how this distance should affects the volume: The Volume Rolloff defines how the volume gets reduced by the distance (linear, logarithmic or a custom curve). The Max Distance value determines at which distance the sound cannot be heard anymore. If you cannot hear your sound you should set this value higher first.

I also recomment to turn off the doppler effect since it makes some strange noise on moving objects.

Ok I finally found why this sound was not audible.
It is due to the Spread parameter that I need to set to 180°.

I think that it could be related to the axis switch caused by 3dsmax.