The wide selection of relaxation audio CDs and mp3s are mostly just soothing tones or music to help with your own meditation. If you are experienced, these might help, but for a lot of people, they won't.
Binaural meditation solutions have been around since the nineteen seventies. By a process called entrainment, it can reliably put you into a calming meditative state without effort on your part.
Your brain generates electrical signals of various frequencies. In order, these are beta, alpha, theta and delta. This ranges from being fully conscious and active to deep, dreamless sleep.
These frequencies are produced by both sides of your brain, all of the time. The strength of the frequencies depends on what you are doing. Meditation is intended to take you to the lower, relaxing frequencies.
It is possible with traditional meditation to reach alpha or occasionally theta, but long practice is needed. It is hard to maintain these levels consistently, or even to know that you have reached them.
Using binaural beat technology, a different tone is played into each ear. The brain resolves these two tones to a single frequency which it generates as a matching electrical signal.
This reliably puts you into this deep meditative state. As long as you are wearing the headphones, it is working. You know you are reaping the benefits of meditation, regardless of how you are feeling or what you think about.
You can't subjectively tell when you are meditating, but with relaxation audios that use binaural beat technology, the doubt is removed. This proven technology means that anyone can meditate like a zen master.