“Speak directly into the mouthpiece keeping mustache out of the opening.”

A  guide for telephone users, 1896:

To Listen: Place the telephone fairly against the ear, with an upward motion, so that the lower extremity or lobe of the ear is gathered in, into the cavity of the telephone; in this position it will be found to fit snugly and comfortably — the lobe of the ear acting as a cushion and at the same time closing out all ulterior sounds, thus enabling the voice to be heard with clearness and precision.

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