Octave generalization and the consolidation of melodic information.

Subjects listened to a standard six-tone melody, followed by a comparison melody. The compar-ison melody was always transposed up four semitones from the standard, and this transposition was either exact or it was inexact while maintaining contour. Subjects judged whether or not the comparison melody formed an exact transposition of the standard. It was found that repetition of the standard melody, before presentation of the comparison, resulted in a significant improvement in performance compared with a condition featuring only a single presentation of the standard. A significant improvement also resulted when the repeated melody was displaced intact an octave higher or an octave lower. However, when the standard melody was repeated such that its com-ponents were displaced alternately to the higher and lower octaves, performance was significant-ly worse than when the standard melody was not repeated at all. Thus, in this paradigm, octave equivalence effects for single tones did not operate in the consolidation of melodic information. It is clear from a variety of evidence that a strong perceptual similarity exists between tones that are separated by octaves (Deutsch, 1973). Several investigators have therefore suggested that pitch be treated as a bidimen-sional attribute: the first dimension represents overall pitch level, or ‘tone height, ’ and the sec-ond defines the position of a tone within the octave, or ‘tone chroma ’ (Meyer, 1904, 1914

NOTE THE OCTAVE ILLUSION IN RELATION TO HANDEDNESS AND FAMILIAL HANDEDNESS BACKGROUND

AbstractThe octave illusion is produced by a dichotic sequence of tones that alternate in frequency between 400 and 800 Hz, such that when the right ear receives 400 Hz the left ear receives 800 Hz; and vice versa. Most listeners obtain the illusion of a single high tone in one ear alternating with a single low tone in the other ear. Further, most righthanders hear the high tone on the right and low tone on the left. The present study examined localization patterns in this illusion as a function of handedness and also of familial handedness background. The effect of handedness was highly significant: the tendency to hear the high tone on the right and the low tone on the left was lower among mixed handers and left-handers than among right-handers. The effect of familial handedness background was also highly significant: the tendency to hear the high tone on the right and the low tone on the left was lower among those with a sinistral familial background than among those with a purely dextral familial background. These findings are discussed in relation to the hypothesis that perception of the illusion serves as a reflection of the direction of cerebral dominance in most individuals

Faster decline of pitch memory over time in congenital amusia

Congenital amusia (amusia, hereafter) is a developmental disorder that impacts negatively on the perception of music. Psychophysical testing suggests that individuals with amusia have above average thresholds for detection of pitch change and pitch direction discrimination; however, a low-level auditory perceptual problem cannot completely explain the disorder, since discrimination of melodies is also impaired when the constituent intervals are suprathreshold for perception. The aim of the present study was to test pitch memory as a function of (a) time and (b) tonal interference, in order to determine whether pitch traces are inherently weaker in amusic individuals. Memory for the pitch of single tones was compared using two versions of a paradigm developed by Deutsch (1970a). In both tasks, participants compared the pitch of a standard (S) versus a comparison (C) tone. In the time task, the S and C tones were presented, separated in time by 0, 1, 5, 10, and 15 s (blocked presentation). In the interference task, the S and C tones were presented with a fixed time interval (5 s) but with a variable number of irrelevant tones in between: 0, 2, 4, 6, and 8 tones (blocked presentation). In the time task, control performance remained high for all time in tervals, but amusics showed a performance decrement over time. In the interference task, controls and amusics showed a similar performance decrement with increasing number of irrelevant tones. Overall, the results suggest that the pitch representations of amusic individuals are less stable and more prone to decay than those of matched non-amusic individuals

No Disillusions in Auditory Extinction: Perceiving a Melody Comprised of Unperceived Notes

The formation of coherent percepts requires grouping together spatio-temporally disparate sensory inputs. Two major questions arise: (1) is awareness necessary for this process; and (2) can non-conscious elements of the sensory input be grouped into a conscious percept? To address this question, we tested two patients suffering from severe left auditory extinction following right hemisphere damage. In extinction, patients are unaware of the presence of left side stimuli when they are presented simultaneously with right side stimuli. We used the ‘scale illusion’ to test whether extinguished tones on the left can be incorporated into the content of conscious awareness. In the scale illusion, healthy listeners obtain the illusion of distinct melodies, which are the result of grouping of information from both ears into illusory auditory streams. We show that the two patients were susceptible to the scale illusion while being consciously unaware of the stimuli presented on their left. This suggests that awareness is not necessary for auditory grouping and non-conscious elements can be incorporated into a conscious percept

Faster decline of pitch memory over time in congenital amusia

Congenital amusia (amusia, hereafter) is a developmental disorder that impacts negatively on the perception of music. Psychophysical testing suggests that individuals with amusia have above average thresholds for detection of pitch change and pitch direction discrimination; however, a low-level auditory perceptual problem cannot completely explain the disorder, since discrimination of melodies is also impaired when the constituent intervals are suprathreshold for perception. The aim of the present study was to test pitch memory as a function of (a) time and (b) tonal interference, in order to determine whether pitch traces are inherently weaker in amusic individuals. Memory for the pitch of single tones was compared using two versions of a paradigm developed by Deutsch (1970a). In both tasks, participants compared the pitch of a standard (S) versus a comparison (C) tone. In the time task, the S and C tones were presented, separated in time by 0, 1, 5, 10, and 15 s (blocked presentation). In the interference task, the S and C tones were presented with a fixed time interval (5 s) but with a variable number of irrelevant tones in between: 0, 2, 4, 6, and 8 tones (blocked presentation). In the time task, control performance remained high for all time in tervals, but amusics showed a performance decrement over time. In the interference task, controls and amusics showed a similar performance decrement with increasing number of irrelevant tones. Overall, the results suggest that the pitch representations of amusic individuals are less stable and more prone to decay than those of matched non-amusic individuals

Absolute Pitch and Tone Language: Two New Studies

ABSTRACT Two new studies provide evidence in favor of the hypothesis that absolute pitch is strongly influenced by a speech-related critical period. The first study examined the prevalence of absolute pitch among students in at the University of Southern California's Thornton School of Music, as a function of age of onset of musical training, ethnicity, fluency in speaking a tone language, and country of early music education. Among those of East Asian ethnicity, performance on a test of absolute pitch was strongly correlated with fluency in speaking a tone language. The advantage of early onset of musical training did not interact statistically with the effects of tone language fluency, and further analyses showed that the results could not be explained by country of early music education. The second study investigated the pitch ranges of female speech in two relatively isolated villages in China. These pitch ranges clustered within each village, but differed significantly across the villages, indicating that, at least for speakers of tone language, the pitch range of speech is heavily influenced by an absolute pitch template that is developed through long term exposure to speech in the environment. Implications of these findings are discussed