548 HEARING. 



quency and coincidences of the vibrations. Two sounds are 

 regarded as consonant, when the ratio of their vibrations is very 

 simple ; and as dissonant, when the ratio is more complex. The 

 rules which determine the most agreeable successions and com- 

 binations of sounds constitute the science of music. 



The power of appreciating musical combinations, and conse- 

 quently the pleasure of listening to them, depends upon a mental 

 faculty seated in a particular portion of the brain, and not upon 

 the acuteness of hearing. A person of the quickest ears may have 

 no music in his soul, and persons of dull ears have often a good 

 ear for music. Many authors have ascribed perception of the 

 musical qualities of sounds to the ear, although there is no relation 

 between acuteness of hearing and musical talents. The ear 

 merely presents the sounds, an inward sense perceives their 

 musical qualities. This inward sense resides in a particular por- 

 tion of the brain, and is proportionate to the perfection of its 

 organisation and size. In all the cases, which I have examined, 

 of flatness or depression of the part of the forehead corre- 

 sponding to this, the perception of music has been defective ; 

 and, in all instances of good musical talent, this part has been 

 full or prominent. The examination of singing birds proves the 

 same thing. Others have with equal absurdity ascribed the idiotism 

 of some persons born deaf to their defect of hearing. Persons 

 may be both idiotic and deaf: but the defect of intellect depends 

 upon the defect of the superior anterior parts of the brain, in 

 quality or quantity. b 



The organs of hearing are situated at the two sides of the head, 

 in a portion of the temporal bone, which is considered the hardest 

 in the human body. The parts which constitute these organs 

 are the external ear, the meatus auditorius, the tympanum, and 

 the labyrinth. The last named part is, there can be little 

 doubt, the seat of sensation, and the other parts serve only to 

 communicate to the labyrinth the impressions from the sonorous 

 agitations of the air. 



The external ear d is a shell-formed cartilage having various 

 elevations and depressions. This appears destined to collect and 



b On both these errors, see Gall, 1. c. 4to. vol. i. 161. sqq. See also 1. c. 

 8vo. t. v. p. 96. sqq. 



e " Sbmmerring, Icones Organor. Humanor. Auditus. Francof. 1806. fol." 

 d " B. S. Albinus, Annotat. Academ. 1. vi. tab.iv." 



