Some noises, although annoying at first, can gradually be ignored, allowing sleep to follow. Studies show people can get used to noises such as city traffic in about one week. However, important noises, like a parent’s baby crying, a smoke alarm or even one’s own name being called, are not easily assimilated and generally snap us awake.

Sleep Affected By Temperature/Climate

The point at which sleep is disturbed due to temperature or climate conditions varies from person to person. Generally, temperatures above 75 degrees Fahrenheit and below 54 degrees will awaken people.

Sleep Affected By Altitudes

The higher the altitude, the greater the sleep disruption. Generally, sleep disturbance becomes greater at altitudes of 13,200 feet or more. The disturbance is thought to be caused by diminished oxygen levels and accompanying changes in respiration. Most people adjust to new altitudes in approximately two to three weeks.

Falling Asleep with White Noise

To understand the promise of white noise, one must first understand its mechanics. In its purest form, it is not really noise at all. White noise, which is also known as white sound, is a combination of sound frequencies in equal amounts. Just like a white beam of light is made up of all the colors in the color spectrum, white noise is made up of all the sound frequencies.

Because it incorporates all sound frequencies from high sounds to very low sounds, it has a very beneficial noise canceling or "masking" effect.