I think that the Sat Nav is the source of many of the bings and bongs, even with the direction instructions muted. As there are around 4 different routes I can take to get to most places, I always put the destination into the Sat Nav in order to check live traffic updates. As previously mentioned, the bings and bongs if you deviate from the Sat Nav’s chosen route are persistent and it brings for other things that I’ve yet to establish! I noticed a ‘bing’ this morning purely because I put the car into reverse!