"Humans, it turns out, are more physiologically aroused by the sound of their own voice than that of others, but unconsciously so."

http://www.tnr.com/article/books-and-arts/magazine/108156/deceptions#

Does Biology Make us Liars?

The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life 
By Robert Trivers
(Basic Books, 397 pp., $28) 

"ARISTOTLE WAS a cynic. Sure, the Bible exhorts to “Love thy neighbor as thyself,” but he knew better. “The friendly feelings that we bear for another,” instructed his Ethics, “have arisen from the friendly feelings that we bear for ourselves.”

Two thousand years later, in 1739, Hume spelled out what the pagan thinker intuited: “I learn to do service to another, without bearing him any real kindness; because I foresee, that he will return my service, in expectation of another of the same kind.”
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Neurophysiology provides some fascinating evidence. Humans, it turns out, are more physiologically aroused by the sound of their own voice than that of others, but unconsciously so. In a classic experiment from the late 1970s, a group of people were each asked to read the same text. The recordings were chopped into short segments and a mosaic master tape was made with snippets from different voices. The participants were then hooked up to a machine measuring their galvanic skin response, which is normally twice as high for hearing your own voice than the voice of another. Then people were played the tape and asked to press a button when they heard their own voice. While some subjects denied their own voice and others projected it onto the voice of others (claiming that someone else was actually them), in all cases the skin had it right."