Hi, I'm new to forum and am at the top end of Old Kent Road (so just in SE1!) Not sure if anyone else on the forum lives near here, but am being driven crazy by intermittent high pitched noise which goes on for about 5 minutes every half hour or so. Doesn't sound like an alarm and I don't have tinnitis nor do I need to see a shrink! It has been going on since Friday last week, day and night. Any ideas?