Interaural Asymmetries Revealed by Dichotic Listening Tests in Normal and Dyslexic Children

2002 ◽  
Vol 13 (08) ◽  
pp. 428-437 ◽  
Author(s):  
Deborah W. Moncrieff ◽  
Frank E. Musiek

Normal and dyslexic right-handed children were assessed with three dichotic listening tests, the Dichotic Digits test, the Competing Words subtest of the SCAN, and the Dichotic Consonant-Vowel test. Performance was measured as both number and percentage of correct responses in the right and left ears. Laterality was defined as a simple difference in percentage between the two ears. Differences across the tests were revealed for all children, with the greatest differences occurring for left-ear responses. Only one dichotic listening test, Competing Words from the SCAN, produced a consistent right-ear advantage across all of the children tested. Between groups of children, differences in performance and in laterality were demonstrated. Using a criterion of poorer than 76 percent correct for the left ear, the Competing Words subtest of the SCAN identified 7 of the 10 dyslexic children as abnormal, with no false alarms in the control group.

1994 ◽  
Vol 52 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Ana Regina Caner-Cukiert ◽  
Arthur Cukiert

Dichotic listening tests have been being used in an increasing frequency to determine in a non-invasive way the cerebral dominance in right- and left-handed patients. This is especially relevant when surgery in eloquent brain areas is being contemplated. A Portuguese version of the dichotic words listening test was developed based mainly on Wexler's protocol. It consisted of 15 pairs of words with a stimulus dominance lower than 50%. They were recorded using natural voice and time and intensity synchronization by means of a specialized software. Each pair of words was presented twice in different channels within each block. The items were randomized and presented with a 300 msec interval between each trial. Four blocks of 30 pairs of words each were created, totalizing 120 trials. In the scoring process, the words heard over the right and left ears were wrote down. The number of times each word was heard over each ear was computed and their values subtracted yielding a partial score for each specific word pair. This process was repeated for all stimuli pair and a final score for right and left predominance was then reached. Thirty-two right handed normal individuals underwent the test 93.8% showed a right ear advantage. These results are very similar to the actual left hemisphere dominance rate in a right-handed population.


Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1183
Author(s):  
Pamela Villar González ◽  
Onur Güntürkün ◽  
Sebastian Ocklenburg

Left-hemispheric language dominance is a well-known characteristic of the human language system. However, it has been shown that leftward language lateralization decreases dramatically when people communicate using whistles. Whistled languages present a transformation of a spoken language into whistles, facilitating communication over great distances. In order to investigate the laterality of Silbo Gomero, a form of whistled Spanish, we used a vocal and a whistled dichotic listening task in a sample of 75 healthy Spanish speakers. Both individuals that were able to whistle and to understand Silbo Gomero and a non-whistling control group showed a clear right-ear advantage for vocal dichotic listening. For whistled dichotic listening, the control group did not show any hemispheric asymmetries. In contrast, the whistlers’ group showed a right-ear advantage for whistled stimuli. This right-ear advantage was, however, smaller compared to the right-ear advantage found for vocal dichotic listening. In line with a previous study on language lateralization of whistled Turkish, these findings suggest that whistled language processing is associated with a decrease in left and a relative increase in right hemispheric processing. This shows that bihemispheric processing of whistled language stimuli occurs independent of language.


2017 ◽  
Vol 26 (4) ◽  
pp. 555-561 ◽  
Author(s):  
Deborah Moncrieff ◽  
Lauren Dubyne

Purpose This study investigated the influence of voice onset time (VOT) on the perception of consonant–vowel (CV) signals during a dichotic listening (DL) task. Method Sixty-two young adults with normal hearing were tested with the English language version of the Hugdahl Dichotic CV (DCV) Test. They were asked to identify 1 CV syllable during 3 DL conditions: free recall (report the syllable heard most clearly), forced right (report the syllable in the right ear), and forced left (report the syllable in the left ear). Averages for number and percent correct syllables were recorded under each condition and across the entire test. Results All subjects demonstrated an overall right-ear advantage (REA) when scores from all 3 listening conditions were averaged. The REA occurred for all VOT pairings except when the long VOT was presented to the left ear, whereas the short VOT was presented to the right ear when subjects produced an average left-ear advantage. The left-ear advantage overcame the structural advantage of the right ear even when subjects were directed to attend to the right ear. This result was consistent with findings of earlier studies done with Norwegian and Australian subjects. Conclusions Listeners' REA may be overcome by interaural temporal differences that favor processing in the listener's nondominant ear during the DCV test. Balanced VOT conditions across the DCV test prevent this effect from producing an overall bias toward the left ear, but clinical DL tests with consonant–vowel–consonant words should be examined for effects of the long VOT on laterality of performance.


Author(s):  
Nattawan Utoomprurkporn ◽  
Chris J.D. Hardy ◽  
Joshua Stott ◽  
Sergi G. Costafreda ◽  
Jason Warren ◽  
...  

Abstract Background Patients with dementia commonly have problems processing speech in the presence of competing background speech or noise. This difficulty can be present from the very early stages of dementia, and may be a preclinical feature of Alzheimer's disease. Purpose This study investigates whether people with dementia perform worse on the dichotic digit test (DDT), an experimental probe of speech processing in the presence of competing speech, and whether test performance may predict dementia onset. Research Design Systematic review and meta-analysis. Data Collection and Analysis A literature search was conducted in Medline, Embase, Scopus, and Psycinfo. We included (1) studies that included people with a diagnosis of dementia and a healthy control group with no cognitive impairment; (2) studies that reported results from a DDT in a free-recall response task; and (3) studies that had the dichotic digit mean correct percentage score or right-ear advantage, as outcome measurements. Results People with dementia had a lower DDT total score, with a pooled mean difference of 18.6% (95% confidence interval [CI]: 21.2–15.9). Patients with dementia had an increased right-ear advantage relative to controls with a pooled difference of 24.4% (95% CI: 21.8–27.0). Conclusion The DDT total scores are lower and the right-ear advantage increased in cognitively impaired versus normal control participants. The findings also suggest that the reduction of dichotic digit total score and increase of right-ear advantage progress as cognitive impairment increases. Whether abnormalities in dichotic digit scores could predict subsequent dementia onset should be examined in further longitudinal studies.


2008 ◽  
Vol 431 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Kenneth Hugdahl ◽  
René Westerhausen ◽  
Kimmo Alho ◽  
Svyatoslav Medvedev ◽  
Heikki Hämäläinen

1981 ◽  
Vol 24 (4) ◽  
pp. 526-534 ◽  
Author(s):  
Nancy Niccum ◽  
Alan B. Rubens ◽  
Charles Speaks

Sixteen aphasic patients were given five different verbal dichotic listening tests. The differences among results obtained on digit test, a high-contrast word test (perception of either vocalic or consonantal information was sufficient for accurate responses), and a vowel-word test (perception of vocalic information was required for accurate responses) were not significant. However, a consonant-word test resulted in significant decreases in both left- and right-ear scores and an increase in the difference in accuracy for the two ears. A consonant-vowel nonsense-syllable test produced further dramatic reductions in performance levels, and the magnitude of difference scores between ears was limited by low levels of performanse for the majority of patients. Attempts to identify relations between patterns of performance on dichotic listening tests and radiographic evidence of lesion location were most profitable when they involved the right-ear (RE) scores on the digit test. The discontinuity in the distribution of these scores corresponded to the presence or absence of damage to the geniculo-temporal system. That is, when the geniculo-temporal system was spared, the RE scores exceeded 75% correct, whereas damage to the geniculo-temporal system was associated with RE scores of less than 50% correct.


1973 ◽  
Vol 53 (1) ◽  
pp. 368-369 ◽  
Author(s):  
Grace Yeni‐Komshian ◽  
Joel Gordon ◽  
Paul Sherman

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