Hi,
Can't say if the circumstances were the same, but what you heard and felt sounds quite similar to what I encountered some years ago.
We were operating a flight from STN TO VLC. The atmosphere was a bit unsettled and on one or two occasions whilst in the cruise through France there was a slight rushing noise associated with significant changes in wind speed and direction. Not a lot of turbulence though. However whilst over the Pyrenees we had a much more significant encounter with much more pronounced changes of wind speed and direction and a louder rushing noise. The turbulence was quite pronounced such that a few passengers and a number of crew were upended. Happily none injured though. The encounter from start to finish probably only lasted 10 to 15 seconds and was preceded and succeeded by almost entirely smooth flight conditions.
As a pilot of quite a few years, this encounter remains one of the few unexplained mysteries. The only conclusion that I came to was that the noise was due to sudden changes to the loading on the wing.
I know this doesn't provide much of an explanation, however, I would discount any air conditioning solutions as crew really should have better things to do than turn on/off air conditioning packs or selecting engine bleeds on/off etc whilst on an approach.