Next to riveting the attention upon some object through the sense of sight, the use of sound is the most important aid in producing the condition of hypnosis.

In fact, very few hypnotists are able to exert complete influence over a subject without in some manner employing this aid.

After the concentration of thought has been at least partially accomplished, then sound is most advantageous. But whatever sounds are made they should always be gentle and monotonous.

Discordant sounds will interrupt a hypnotic seance, and intermittent sounds are equally undesirable.

Let us take for example the simplest and most frequent instance of the production of hypnosis the mother putting her babe to sleep.

How soft and soothing is her lullaby, sung in monotonous tones over and over again, with the desire that her babe shall sleep and perfect confidence in her own ability to make it do so.

Oriental magicians, who are expert hypnotists, invariable chant unintelligible words in monotonous tones while placing their subjects under control. Such chanting produces a most desirable drowsiness.