TABLES 132-135. 

 MISCELLANEOUS SOUND DATA. 



TABLE 132. A Fundamental Tone, Its Harmonics (Overtones) and the Nearest 

 Tone of the Equal-tempered Scale. 



I4Q 



NOTE. Overtones of frequencies not exact multiples of the fundamental are sometimes called inharmonic partials. 

 TABLE 133. Relative Strength of the Partials in Various Musical Instruments. 



The values given are for tones of medium loudness. Individual tones vary greatly in quality and, therefore, in 

 loudness. 



TABLE 134. Characteristics of the Vowels. 



The larynx generates a fundamental tone of a chosen pitch with some 20 partials, usually of low intensity. The 

 particular partial, or partials, most nearly in unison with the mouth cavity is greatly strengthened by resonance. Each 

 vowel, for a given mouth, is characterized by a particular fixed pitch, or pitches, of resonance corresponding to that 

 vowel's definite form of mouth cavity. These pitches may be judged by whispering the vowels. It is difficult to sing 

 vowels true above the corresponding pitches. The greater part of the energy or loudness of a vowel of a chosen pitch 

 is in those partials reinforced by resonance. The vowels may be divided into two classes, the first having one char- 

 acteristic resonance region, the second, two. The representative pitches of maximum resonance of a mouth cavity 

 for selected vowels in each group are given in the following table. 



TABLE 135. Miscellaneous Sound Data. 



Koenig's temperature coefficient for the frequency (n) of forks is nearly the same for all pitches. n t 

 o(i o.opoii* C), Ann. d. Phys. 9, p. 408, 1880. 



Vibration frequencies for continuous sound sensations are practically the same as for continuous light sensation, 

 10 or more per second. Helmholtz' value of 32 per sec. may be taken as the flicker value for the ear. Moving pictures 

 use 16 or more per sec. For light the number varies with the intensity. 



Pitch limits of voice: 60 to 1200 vibrations per second. 



Piano pitch limits: 27.2 to 4138.4 v. per sec. (over 7 octaves). 



Organ pitch limits: 16 (32 ft. pipe), sometimes 8 (64 ft.) to 4138 (ij in.) (9 octaves). 



Ear can detect frequencies of 20,000 to 30,000 v. per sec. Koenig, by means of dust figures, measured sounds from 

 steel forks with frequencies up to 90,000. 



The quality of a musical tone depends solely on the number and relative strength of its partials (simple tones) and 

 probably not at all on their phases. 



The wave-lengths of sound issuing from a closed pipe of length L are *L, 4^/3, 4^/5, etc., and from an open pipe, 

 2L, 2L/2, 2L/3, etc. The end correction for a pipe with a flange is such that the antinode is 0.82 X radius of pipe 

 beyond the end; with no flange the correction is 0.57 X radius of pipe. 



The energy of a pure sine wave is proportional to n*A 2 ; the energy per cm 3 is on the average 2pir*U*A-/\' 1 ; the energy 

 passing per sec. through i cm* perpendicular to direction of propagation is 2pir*U 3 A*/\*; the pressure is \(y + i) 

 (average energy per cm 3 ); where n is the vibration number per sec., X the wave-length, A the amplitude, V the veloc- 

 ity of sound, p the density of the medium, J the specific heat ratio. Altberg (Ann. d. Phys. n, p. 405, 1903) measured 

 sound-wave pressures of the order of 0.24 dynes/cm 2 = 0.00018 mm Hg. 



SMITHSONIAN TABLES. 



