CONTENTS:
UEBER DAS ERKENNEN DER SCHALLRICHTUNG. By J. v. Kries.
ZUR PSYCHOLOGIE DER KAUSALITAET. By Th. Lipps.
ZUR INTERAUREALEN LOKALISATION DIOTISCHER WAHRNEHMUNGEN. By Karl
L. Schaefer.
ZUR PSYCHOLOGIE DER FRAGE. By Rich. Wahle.
UEBER NEGATIVE EMPFINDUNGSWERTE (I). By H. Ebbinghaus.
VERSAMMLUNGEN: Internationaler medizinischer Kongress zu Berlin 1890. I. Sektion für Augenheilkunde. Referiert von Claude du Bois-Reymond.—II. Sektion für Ohrenheilkunde. Referiert von Krakauer.
LITERATURBERICHT.
Professor J. von Kries examines the hypotheses propounded of late concerning the recognition of the direction in which sound-waves reach the ear. Professor Preyer maintains that different irritations, according to the source of sound, take place in the semi-circular canals, and Münsterberg, on the basis of his own experiments, has with some essential modifications accepted Preyer's views. The author devotes his chief attention to the localisation of sounds originating either to the right or to the left of the median plane. The experiments were made with two movable whistles, the intensity of which could easily be regulated. The result was that concerning right and left direction, and also with regard to simultaneous sounds from both directions at a different pitch, each note could be correctly localised. He adds that, so far as he can judge, even he who adopts Münsterberg's view has to fall back upon a comparison of the intensity in both ears. A localisation of whistle-sounds in the median line, be it in front or at the back, was not so certain. A single tone was, upon the whole, correctly localised; yet it was difficult to discriminate two sounds in the median plane.
In another article on the same subject, entitled On Interaureal Localisation of Diotic Sensations Karl L. Schaefer of Jena recapitulates in brief the monotic and diotic experiments made by Silvanus B. Thompson, Purkynés, Urbantschitsch, and Preyer; completing the inquiries of Fechner on the subject he states the following result: "Let two tuning forks be placed at an equal distance from the median plane in front of the ears, so that their sound is medianly localised: 1) Synchronal vibrations of any pitch, at the same distance, and in exactly opposite directions, produce median oscillations; 2) If the forks are moved a tempo to the right or to the left, i. e. in the same direction, the sound rolls from ear to ear, so long as the motions are not too rapid; 3) If they are executed as quickly as possible the vibrations have their seats in both ears."