As far as aviation sounds go, nothing was as evocative (for me) when I was growing up, as when I was lying in bed as a schoolboy, half asleep around 10pm, and hearing the distinctive whine of a Vanguard (Merchantman/Mudguard, your choice) trundle to the holding point of my local, then strangely sound quieter under full beans than it was when starting up or taxiing. I lived about a mile from the departure threshold, and on some clear winter nights it was spookily loud. But strangely soothing...
