Yes.. When you lie on your back, you must be perfectlly still. What you are trying to do, is make your brain think that your body has gone to sleep, and so you enter sleep paralysis, which is the 'sinking' and 'patterns and noises' you described. The patterns and noises and sinking are
not definatelly what you will experience. Some people experience a vibrating, a rocking feeling, a sinking feeling, floating feeling, a feeling as if someone is pushing on your chest (also known as the 'old hag'), hypnagogic imagery (the patterns or images), noises such as people talking or buzzing sounds, and many other things. However; some people don't experience anything at all.
Please read this. It is a comprehensive guide to WILDing by the Dream Guide Team. It will explain everything you need to know, plus it has links to other WILD guides by other users.
http://www.dreamviews.com/community/...ad.php?t=66238
Happy WILDing. :)