Ear differences in the recall of fricatives and vowels.

This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Two experiments on the free recall of dichotically presented synthetic speech sounds are reported. The first shows that the right ear advantage for initial fricative consonants is not simply a function of the recognition response class, but that it is also a function of the particular acoustic cues used to achieve that response. This is true both for the whole response, and for the constituent phonetic features. The second experiment shows that when both the response class and the particular stimuli presented on certain trials are held constant, the right ear advantage for the constant stimuli can be influenced by the range of other stimuli occurring in the experiment. Vowels show a right ear advantage when, within the experiment, there is uncertainty as to vocal tract size, but they show no ear advantage when all the vowels in the experiment are from the same vocal tract. These results are interpreted as demonstrating that there are differences between the ears, and probably between the hemispheres, at some stage between the acoustic analysis of the signal and its identification as a phonetic category. Introduction Under certain conditions, sounds which enter one ear may subsequently be more efficiently recalled or recognized than similar sounds entering the other ear (Kimura, 1961a,b, 1964). Differences between the ears tend to be obtained more reliably when different sounds enter the two ears simultaneously than when only one ear is stimulated, either with one (Corsi, 1967) or with two simultaneous signals (Shankweiler, in press). Monaural stimulation can give significant ear differences but such experiments have required larger numbers of subjects than the usual dichotic paradigm (Bakker, 1968, 1970). The type of stimulus material used is probably the only determinant of which ear gives better …