I was wondering if anyone practices meditation using products like those on the following website ( http://www.mind-tek.com/products.html )? What was your experience like using these products and where they beneficial?

A note for those unfamiliar with such products; they play certain sounds which have an effect on brainwave patters. The following website explain this better; http://www.hemi-sync.com/store/pages.php?pageid=15