PHYSICAL CHARACTERISTICS OF SPEECH AND MUSIC 351 



language that contribute toward the loudness of speech. In Fig. 1 

 the ordinates are proportional to the pressure change in bars and the 

 abscissas are time intervals of .01 second. The eighteen fundamental 

 sounds in this sentence are joined together without the stream of sound 

 being interrupted except for the stops t, k and ch. The stop consonant 

 b is voiced so that although the vocal cord sound is interrupted by 

 the closing of the lips, it continues to sound in a subdued way until 

 the stop is removed and the e sound begins. Pauses, that is, silent 



Fig. 2 — Melodic curves: "Joe took Father's shoe bench out" — spoken. 



intervals, are made between sentences and sometimes between words. 

 It will be noticed that a brief pause was inserted at the intervals .17 

 to .21 and .32 to .335 and .34 to .41 and 1.16 to 1.18 seconds. There is 

 no such pause between "shoe" and "bench." 



Speech, then, consists of a series of comparatively steady states of 

 vibration joined together in time, either by silences or transitions from 

 one steady state to another. Each one of these steady states is 

 characterized by a pitch and a tone quality, and the sequence is 



