A text-book of physiology, for medical students and physicians . presents such a pic-ture as is represented in Fig. 175, in which the crestsof the waves are at a fixed interval for each tone. Ifat these intervals the corresponding hair cells andnerve fibers are supposed to be stimulated, then ourconsciousness would recognize each note by its appro-priate interval. For the application of this theory to musical harmony—combinational tones and beats—reference must be made to the original. Sensations of Harmony and Discord.—The combination ofnotes to produce various harmonies or intentional discor
A text-book of physiology, for medical students and physicians . presents such a pic-ture as is represented in Fig. 175, in which the crestsof the waves are at a fixed interval for each tone. Ifat these intervals the corresponding hair cells andnerve fibers are supposed to be stimulated, then ourconsciousness would recognize each note by its appro-priate interval. For the application of this theory to musical harmony—combinational tones and beats—reference must be made to the original. Sensations of Harmony and Discord.—The combination ofnotes to produce various harmonies or intentional discords is a partof the theory of music, but attention may be called briefly to thephysiological explanation offered by Helmholtz to account for thefact that certain notes when combined give us a disagreeable sen-sation, appear rough and unpleasant; while others, on the contrary,produce pleasant sensations. Discord or dissonance is due, accord- * Baginsky, Virchows Archiv f. pathol. Anat. 94, 65, Ewald. Archiv f. d. gesammte Physiologie, 76, 147, Fig. 175.—To il-lustrate the idea ofa fixed sound wave.—(.Ewald.) The illus-tration shows a fun-damental note and itsfirst overtone. 392 THE SPECIAL SENSES. ing to Helmholtz, to the beats produced when two dissonant notesare sounded together. On the physical side the beat,—that is, arhythmical variation in the intensity of the sound,—is due to thephenomenon of interference. If the rates of vibration of two notesare such that at certain intervals the crests of the waves fall to-gether and again the crest of one coincides with the hollow of theother, the sound sensations will be periodically increased anddecreased. While there is no fundamental explanation for thefact that a regularly varying intensity of sound is disagreeable, itis a well-known phenomenon and it finds analogies in the othersensations,—for instance, in the very disagreeable effect of a flick-ering light. When two notes are sounded together the nu
Size: 879px × 2843px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookautho, bookcentury1900, bookdecade1900, booksubjectphysiology
