Sound machines are most effective when placed between yourself and the greatest source of noise. This may mean that instead of simply placing the unit on the bedside table, it is more beneficial to put it beneath a window to block traffic sounds, near an interior door to mask television or voices from another room, or up against a thin wall to minimize the sounds of noisy neighbors, to give a few common examples. You'll also want to try adjusting the volume of the sound machine in these different locations. With a little fine-tuning, you'll soon have the ideal noise-masking setup for your personal sound environment.