I read with interest the letter 'Mysterious Sound' which appeared in the June issue. I also encountered a similar mysterious sound last year on 17th June, 2001, on a ridge named Druim Coire nan Laogh situated in the Lochaber area, several miles west of Loch Arkaig. It was in the forenoon, on a fine day when the weather pattern was more or less identical to that described in Charlie's letter. I was suddenly distracted by a loud noise apparently coming from a spot a short distance to the north. The noise, which lasted all of five seconds, ceased just as suddenly as it had started. It was as if intense gusts of wind were violently flapping a large and heavy sheet of polythene. I can still recall standing there for a moment somewhat perplexed as all I could feel at that moment was the same gentle breeze which had been present since gaining the ridge. I walked over to the spot to investigate, half expecting to find a discarded bivvy bag, tent flysheet, or something similar. Apart from a rocky outcrop, the terrain was relatively open; the search took only a matter of moments, and nothing could be found. In spite of the calm conditions, perhaps it was a sudden gust which had blown something off the ridge and down the north-facing slopes? I made a further short detour to have a look. Again, the expected polythene sheet was nowhere to be seen. I continued on my way, and the remainder of the day passed off without further incident. On my descent from Bidean a' Chabair I had occasion to pass by the same spot and took the opportunity for a further search of the area to no avail.
In Charlie Stephen's letter he mentions the noise moving towards, and passing him. This differs from my experience where the noise seemed to come from, and stay in, one place. I'm convinced that the cause has to be connected in some way to a freak effect of the weather.

Leslie Barrie