Secondly, we can introduce sounds that help to shut out the wrong noises, and that also help us to relax. White noise, such as that produced by a fan or a humidifier does help to drown out the trucks and the barking dogs. So does a radio playing quietly in the background. Unfortunately, these sounds in themselves tend to be arousing and stressful rather than relaxing. This is to do with two factors: pitch and beat. High frequencies sounds are energizing, whilst low frequencies are relaxing. White noise is fairly high frequency, as is most music played on the radio - especially if played through a cheaper system with a poor bass response. Also, most popular music has a fast beat. Disco music is the most obvious example of this. No doubt at times you have found yourself tapping or nodding in time with the beat of some catchy music. This is called "entrainment," and describes the fact that our bodies like to align themselves with the rhythms around us. Our heart rates do the same - in general, as you listen to fast music or a fast beat (such as with rap music), your heart rate will speed up; when you listen to slow music, it slows down.

For sleep, we need to listen to low pitched sounds with a slow rhythm. We should try for a beat of 50 to 60 Hz, the rate or our resting hearts. Where do we find these sounds? Some classical music and some nature sounds qualify. I recommend recordings made specially for relaxation. Some of the best are made by Steven Halpern. The Sound Health Series CDs, called "Relax" and "De-Stress" are great. Play them quietly as background noise to drown out the dogs and to create a peaceful environment in the child's bedroom. If he wakes often during the night, consider playing continuous-play CD.

Color and Light. Not only are our bodies and minds sensitive to the frequencies and rhythms or sounds, we are also profoundly affected by light and color. This is well know by supermarkets and football teams! The supermarkets use green/blue tinged lights to make the vegetables look greener and fresher, but red tinged light on their meat counters. This is done very subtly, but very effectively. The colors on the product packaging are equally carefully chosen and designed to motivate you to buy. The stores are brightly lit, and may have "muzak" playing. All of this is done to make you feel up-beat and comfortable. The longer you stay, the more you will spend. Contrast that with some dingy shops that you know. In the same way, some football clubs will paint their changing rooms in different colors - red for the home team, as it is activating and arousing; and blue for the away team, as it is relaxing and calming.

Blue is for serenity, green for harmony and peace, pink instills warmth and cosiness. All of these, especially if in muted tints, are ideal of bedrooms, although blue and green may produce too cold an atmosphere. On the other hand bright and vibrant colors such as yellows and reds will rev us up and keep us awake. The effects are subtle and certainly not conscious, but even so are very real.