White noise machines are electronic devices that generate simulated soothing nature sound effects such as rain, wind or surf. They help insomnia sufferers go to sleep by promoting relaxation and replacing mental voices, disturbing household noises, traffic noises and their partner's snoring. They assist parents in putting toddlers to sleep. They mask noise disturbance of tinnitus ear disease and CPAP-continuous positive airway pressure-devices used by sleep apnoea sufferers. Individuals find them useful in offices for overwhelming noise distractions. These machines however, do have some negative effects.
Direct exposure of the ears even to moderate volumes of noise for hours at a time can weaken auditory abilities. Hence, the sound volume deployed by white noise machines can have deafening effects in the long term despite being at a reasonable volume. Using white noise machines in conjunction with pillow speakers or earphones intensifies this adverse impact.
An Increase in Stress and Blood-pressure Levels
White noise is merely random nature sounds of all frequencies mixed together. It is not rhythmic like soft music that is considered therapeutic. Some people may dislike such tones. For them white noise machines may trigger higher stress, fatigue and hypertension, consequently hindering sleep, and inviting a host of other problems including heart ailments. White noise machines are useful only if the sounds generated have a calming effect. Machines that allow customisation of sound as per personal preference are wiser options.
Lower Concentration and Mental Clarity
Unlike Mozart and Bach music of 60 heats per minute, white noise emitted by machines may actually degrade the brain's performance from high alertness producing 8 to 13 Hz alpha waves to lower quality 14 to 20 Hz beta brain waves. This will reduce concentration, mental lucidity and therefore the productivity and quality of life. White noise machines contain digitally recorded nature sounds and cannot effectively substitute real natural environmental sounds such as chirping birds, careening waterfalls, gushing winds, voices and footsteps. Hence, they cannot provide the same quality internal quietude and tranquillity that "sounds of silence" can furnish us.
Harmful Effects of Looping
Some white noise machines play a few minutes of recorded white noise repeatedly by looping the ends with the beginning of the recording. The listener begins to discern the breaks in between when he listens to the white noise for a while and this may irritate and annoy him. White noise machines that synthesise white noise on their own do a better job in avoiding this demerit, but they are very expensive.