ON THE PRODUCTION OF AN ARTIFICAL HISS. 



By E. B. TITCHENER. 

 (Read November 6, 1914.) 



In Nature of Alay 29, 1913, Lord Rayleigh asked to be told 

 " how to make an artificial hiss." I replied that, if Kohler's ob- 

 servations are reliable, " a Galton whistle, set for a tone of 8,400 

 V. d., will give a pure sT ^ Lord Rayleigh, however, was not 

 impressed by the suggestion.^ 



It occurred to me that the question might be put to the test of 

 experiment. The sound of a Galton whistle set for 8,400 v. d. 

 might be imitated by the mouth, and a series of observations might 

 be taken upon material composed partly of the natural (mouth) 

 sounds and partly of the artificial (whistle) tones. If a listening 

 observer were unable to distinguish between the two stimuli, and 

 if the mouth-sound were shown, phonetically, to be a true hiss, then 

 it would be proved that the whistle also gives an 5, and Lord Ray- 

 leigh would be answered. 



The experiment was more troublesome that I had anticipated ; 

 but I may say at once that it has been carried out, and with affirm- 

 ative result. 



We used an Edelmann-Galton whistle (No. 423) actuated by 

 a rubber bulb.^ Our first difficulty was to find a competent experi- 

 menter. For the sound of the whistle is clean-cut, uniform, so to 

 say dogmatic. This very definite stimulus has to be duplicated by 

 a certain setting of tongue and lips, and by voluntary regulation and 



1 Nature, July 3, 1913 ; W. Kohler, Zeits. f. Psych., LXIV., 1913, 93. 



2 Nature, July 31, 1913. 



3 The bulb that comes with the instrument must soon be renewed. It 

 may be worth while to point out that bulbs of white or grey sulphur-coated 

 rubber should never be employed ; the fine dust chokes the mouthpiece and 

 plays havoc, e. g., with terminal determinations. We use a black rubber that 

 is slightly more flaccid than that furnished by Edelmann. 



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