172 



ANNUAL REPORT SMITHSONIAN INSTITUTION, 19 32 



play a part. As to pitch, it is probable that the majority of people 

 find shrill sounds more offensive than low. They find, for example, 

 the high-pitched motor horn, to the staccato use of which the Paris 

 taxi driver is so addicted, more irritating than the lower-pitched 

 horn which normally obtains in Great Britain, This impression is 

 confirmed by the work of Laird and Coye (Journ. Acoust. Soc. Amer., 

 1929), who found that annoyance is a function of both loudness and 

 pitch, high pitches being intrinsically more annoying than low or 

 medium pitches, and very loud high pitches being especially irri- 



Good hearinc) 

 condiVions 



Sal'isfacl'erij wifh 

 al'I'enl'ive lisCeninc] 



Unsat'isfacl'orij 

 hearinc) condiVions 



"0 20 40 60 80. 



Backaround e\ noise in decibels 



E{{ectr of exlfraneous noise on infelliqibilit'tj o| speech 

 of nermal loudness (50 db) — Knudsen. 



Figure 4 



tating. In the case of pitches below about 600 cycles per second, the 

 annoyance was, however, purely a matter of loudness. In this con- 

 nection it is of considerable interest to note that the range of pitches 

 which man normally employs in his own speech appears to be the 

 least annoying to him. The irritation produced by certain tenor and 

 soprano voices is claimed by Laird and Coye as being in harmony 

 with their findings. 



The annoyance produced by complex noises such as those resulting 

 from motor horns appears to be largely influenced not only by sheer 

 loudness but also by the presence of strong high-frequency compo- 

 nents as well as by strong inharmonic components. 



Some such explanation may also account for the fact that al- 

 though, for example, two fans or two vacuum cleaners may appear 



