A new theory of hearing / by C. Herbert Hurst.

  • Hurst, C. Herbert (Charles Herbert), 1856?-1898.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: A new theory of hearing / by C. Herbert Hurst. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    5/38 (page 323)
    pressure on its outer surface while the pressure on its inner surface remains nearly constant, produces effects upon the ossicles of the middle ear. To determine whether the ossicles move as a whole or as some have maintained they “transmit the sound molecularly” it is necessary to make a rough estimate of the velocity of sound in them and to consider what is the length of a sound wave when transversing the series of ossicles. To determine this accurately is not easy but it is quite unnecessary: an error of even 10000 per cent, is of no consequence. The lowest audible tone is not the same for all hearers, but few if any can hear as a tone any sound due to less than 10 vibrations a second. A pure tone of 40000 vibrations is audible to some and the pro- duction of beats and beat-tones by simultaneous action of two sets of waves some of which in one series follow others in the other series at smaller intervals of time than this has been demonstrated by Koenig and others. It is only necessary therefore to consider whether the time required for transmission of a sound wave through these ossicles lies between second and iVth second, or above or below those limits. The mere consideration of the question even without answering it, suffices to show that the distinction drawn between the two modes of transmission is a distinction in words rather than in phenomena. If the wave length in the ossicles is much smaller than the length of the chain it would be said that the transmission is “molecular;” if it is much longer than the chain it would be said that it is “ molar.” The nature of the transmission is, however, identical in the two cases and the distinction is purely verbal and useless. The transmission of energy along a pulled bell-wire is of the same nature as the transmission of a sound wave: the energy is indeed transmitted as a true sound wave of