Synchronisation of sound and object animation

[Ced!]

I have an animation, in 3 parts that lasts 5 seconds.
It is accompanied by a sound that also lasts 5 seconds (sound in 3 parts too).
When I start the game, it usually works fine, but sometimes the sound is out of sync.
I tried removing the sound from the animation and adding it as 3D sound in makeitgood but then a slight discrepancy appears, which becomes huge after three laps of the track.
I’ve synchronised sounds with each other before and it works; but sound and object animation...

[Ced!]

All in all, I realise that there’s also a discrepancy when sound is included in the custom animation, but it seems to me that it’s less noticeable.