So I was following up on an acoustics research project we completed last year into unexplained noise events in ceilings, and I found the amount of threads across different websites asking about this problem quite worrying!
Your description of the noise and when it occurs sounds similar to what we encountered during the project. A report on these cracking events has now been published by the UKTFA online at the following website address:
Whilst it doesn't provide all the answers and its a small sample, in the five sites that were investigated for the cracking noise the standard gypsum ceiling boards were removed and replaced with resilient bars (metal channels) and higher-density gypsum boards (15 mm, ~12.5 kg/m2). No further instances of the noise has been reported since these remedial works, so this could be an option for you if you're going to try and stop the noise.
Anyway, read the report and see if it rings any bells!