Transactions of the Medical Society of King's College, London.

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Credit: Transactions of the Medical Society of King's College, London. Source: Wellcome Collection.

    130/262 (page 120)
    It has been remarked by Weber and others that the tracheal tube is so short that it cannot affect the pitch of the note produced at the glottis. The experiments of M. Savart have shown that the flexibility of its parietes compensates for its want of length, and enables it to vibrate synchronously, and therefore to give forth sounds equally grave with those of the glottis ; thereby reinforcing the sound which would indeed be produced by the glottis alone, though with much less intensity without this aid. The falsetto voice has always been considered a most em- barassing subject. Dodart and Bonnati supposed that it was produced in the cavity above the larynx. Weber suggested that the falsetto notes were produced by the development of nodal points in the vocal cords. These opinions, however, are mere conjectures, without any proof. It was observed by Bishop that, when the voice passed from the highest note of the chest voice to the first note of the falsetto register, the crico-thyroid chink suddenly opened, so that the cords were relaxed at the same time the larynx fell. As the voice be¬ came higher in the falsetto range the crico-thyroid chink again closed, and the cords stretched. It is supposed by Bishop, that in the production of the chest voice the cords vibrate i n their whole length, but in the falsetto, the cords are placed in contact posteriorly, so that a portion only of the length can vibrate; as the falsetto notes become higher, the cords are tightened, but still kept in contact posteriorly. Muller considers that the falsetto notes are produced by the vibration of the inner edge only of the vocal cords ; the thyro-arytasnoid muscle acting as a damper, and preventing the outer portion of the cords from being thrown into vibration. I he influence ol the epiglottis on the voice has always been a disputed subject. Liscovius asserts that it has no in-