Originally Posted by YeaF30
Last night I got in my 328i and started it up only to hear the BMW gong alert noise completely distorted. I have posted a video of the sound by unbuckling my seat belt while the car was moving. The sound seemed to be slowed down. When I got back in the car this morning, all was okay but I wanted to post the video to see if anyone else had a similar issue.
It does not sound like distortion from a blown power amp stage or a failing loudspeaker.
Rather, the sound has the characteristic sound of jitter or latency typically found in packetized networks.
The fact that it cleared up helps to confirm it is not an amp or a speaker.
However, the fact that it is unusual could point to an issue with one of your cars electronic busses.
A seatbelt chime is generally a playback of a previously sampled sound. Thus, I would keep an eye on this. The seatbelt chime is a high priority process; however, it is not getting the priority it deserves due to a fault with another component. Or, there is increased latency on one of your cars networks or busses. This can be due to the lack of an appropriate ACK. This could result from something as simple as a bad bus or network connection. Or, it could point to something like a failing component starving the network or bus.