Text: The pinna or auricle is said by some authors to help us to hear by reflecting sound into the meatus and by propagating it through its substance to the bony part of the meaus and thence to the membrana tympani. Reflection can only be helped by the large hollow behind the meatus called the concha, and by the point in from of the meatus called the tragus, the concha reflecting the vibrations on to the tragus, and this reflecting them in turn into the meatus. The other parts of the pinna have been supposed to assist sound by conduction, their various folds having the function, according to this view, of receiving vibrations in various planes perpendicularly and thus most favourably for propagation. Another view regards these folds as instrumental in neutralizing conflicting sound waves, that the principal vibrations may be able to enter the meatus without interruption. All these are mere speculations. An animal with moveable ears, such as a horse, turns his ears to the source of sound, but we have no such power, the extrinsic muscles of our ear are generally quite functionless, and never, in any case, possess this power, the only one which would help us to utilize our pinna. Mr. Toynbee believed the pinna to be quite functionless in man.

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