Sharper Image Sound Soother 20
Best overall. The critics like the fact that this machine has so much variety — everything from wind chimes to fog horns to city sounds. The unit itself is light weight, portable, very easy to use and emits no light.
www.sharperimage.com

Obusforme Sound Therapy Relaxation System
Best value. Features 10 different sounds. Battery operated, with a large volume knob and user-friendly design.
www.livingincomfort.com

Brookstone Tranquil Moments Sound Therapy System
Features 12 categories of sounds, from deep pulsations to sounds from outer space. One drawback is that the light the unit emits might keep restless sleepers awake.
www.brookstone.com

Marpac SleepMate 980
This unit generates a white noise similar to a whirring fan with adjustable volume and pitch. The critics wish it provided more choices of sounds.
www.marpac.com

Target Homedics Tranquil Rains Rainfall and Sound Machine
Although this unit features six sounds, from chirping birds to wind chimes, the critics found it cumbersome to setup and operate. The unit's dripping water and mirrors are also too visually distracting.
www.target.com