Reverse speech

Reverse speech is a hypothesis first put forward by David John Oates. It was widely publicized on the radio show of Art Bell.

Oates' claim is that on average, once every 15-20 seconds of casual conversation, a person conveys two related sentences, only the forward message we can hear consciously. The second message is embedded backwards unconsciously into the person's speech. Backward messages in rehearsed and public speech do not occur as often; about once every 60-90 seconds a message is conveyed through reversed speech. These two modes of speech, forward and backward, are dependent upon each other and form an integral part of human communication. One mode cannot be fully understood without the other mode. In the dynamics of interpersonal communication, both modes of speech combined communicate the total psyche of the person, conscious as well as unconscious.

This means that if a person's statement was recorded and played backwards, the speaker's unconscious thoughts could be heard. The most famous recording that allegedly demonstrates this is the speech given by Neil Armstrong at the time of the moon landing in 1969. If played backwards, the words "small step for man" sound somewhat like "Man will space walk!"

Many videos on YouTube that relate to reverse speech almost always lower the pitch of the reversal to make the subliminal words more clear

Intentional reversal of speech without a technical device is called phonetic reversal.

While the theory that the human brain can express otherwise hidden thoughts by embedding them as reversed speech into the intended speech is quite fascinating, there are simpler theories that explain these astonishing messages. A quite simple and well published explanation for this phenomenon is, that the human brain desperately and partially successfully tries to make sense out of the noise, as soon as it expects that noise to be a spoken language.

Another likely explanation of Reverse Speech phenomena is that the power of suggestion is used to nudge the listener to hear what the presenter wants them to hear. David John Oates, for example, almost always tells the listener in advance what they should expect to hear, thereby planting a suggestion that would make the listener more likely to actually "hear" something. Independent studies have shown that when listening to the same clips without being told in advance what to expect, the average listener will either hear something entirely different, or just hear plain gibberish (see "Criticisms of Reverse Speech" in External Links).