Development, validity, reliability and normative data of the Persian Phonemic Synthesis Test (P-PST).

Objectives: This study was conducted to develop the Persian version of the Phonemic Synthesis Test, evaluate its psychometric properties and generate normative data.Design: Test development, including the optimisation of materials, determining content and face validities and assessing the psychometric properties.Study samples: Overall, 425 subjects participated in this study in three different stages. Ten experts participated in the content validity assessment stage. The face validity was determined by taking the views of 17 subjects, including children diagnosed with APD, normal children and experts. The psychometric properties were evaluated with 395 normal children aged 7 to 11, divided into five age groups. All the participants were retested after four weeks for evaluating the test-retest reliability.Results: The results revealed the strong content and face validity of the test. No significant differences were observed between the genders. Significant differences were observed in the quantitative and qualitative scores among the age groups. The Spearman correlation coefficient showed that the scores of the test and retest were strongly and positively correlated (r > 0.9). The findings showed many similarities with the data reported in the original American English Phonemic Synthesis Test.Conclusions: The Persian Phonemic Synthesis Test is a reliable and valid test for auditory processing assessments in Persian-speaking children.

Normative data for diagnosing auditory processing disorder in Norwegian children aged 7-12 years.

OBJECTIVE: The main purpose of this research was to obtain normative data for auditory processing tests for Norwegian speaking children. DESIGN: Participants were administered routine audiological tests and an auditory processing test-battery consisting of Filtered Words, Competing Words, Dichotic Digits, Gaps In Noise, Duration- and Frequency Pattern, Binaural Masking Level Difference and HIST Speech in Noise test. A group of 10-year-old children were retested after two weeks. The effects ear, age and gender and the test-retest reliability were investigated. STUDY SAMPLE: There were 268 normal hearing children aged 7-12 years who participated in the study. RESULTS: Results revealed no differences between genders. The children showed improving performance by age on all tests, except from the Gaps In Noise and Binaural Masking Level Difference. As expected, the children showed a right ear advantage on dichotic speech tests that decreased with age. The test-retest reliability for the tests was good, with a small learning effect on the Filtered Words test. CONCLUSION: Normative data were established and the preferred tests for diagnosing Auditory Processing Disorder were suggested for Norwegian children aged 7-12 years.

The Dichotic Digits difference Test (DDdT): Development, Normative Data, and Test-Retest Reliability Studies Part 1.

BACKGROUND: The dichotic digits test is one of the most widely used assessment tools for central auditory processing disorder. However, questions remain concerning the impact of cognitive factors on test results. PURPOSE: To develop the Dichotic Digits difference Test (DDdT), an assessment tool that could differentiate children with cognitive deficits from children with genuine dichotic deficits based on differential test results. The DDdT consists of four subtests: dichotic free recall (FR), dichotic directed left ear (DLE), dichotic directed right ear (DRE), and diotic. Scores for six conditions are calculated (FR left ear [LE], FR right ear [RE], and FR total, as well as DLE, DRE, and diotic). Scores for four difference measures are also calculated: dichotic advantage, right-ear advantage (REA) FR, REA directed, and attention advantage. RESEARCH DESIGN: Experiment 1 involved development of the DDdT, including error rate analysis. Experiment 2 involved collection of normative and test-retest reliability data. STUDY SAMPLE: Twenty adults (aged 25 yr 10 mo to 50 yr 7 mo, mean 36 yr 4 mo) took part in the development study; 62 normal-hearing, typically developing, primary-school children (aged 7 yr 1 mo to 11 yr 11 mo, mean 9 yr 4 mo) and 10 adults (aged 25 yr 0 mo to 51 yr 6 mo, mean 34 yr 10 mo) took part in the normative and test-retest reliability study. DATA COLLECTION AND ANALYSIS: In Experiment 1, error rate analysis was conducted on the 36 digit-pair combinations of the DDdT. Normative data collected in Experiment 2 were arcsine transformed to achieve a distribution that was closer to a normal distribution and z-scores calculated. Pearson product-moment correlations were used to determine the strength of relationships between DDdT conditions. RESULTS: The development study revealed no significant differences in the adult population between test and retest on any DDdT condition. Error rates on 36 digit pairs ranged from 1.5% to 16.7%. The most and the least error-prone digits were removed before commencement of the normative data study, leaving 25 unique digit pairs. Average z-scores calculated from the arcsine-transformed data collected from the 62 children who took part in the normative data study revealed that FR dichotic processing (LE, RE, and total) was highly correlated with diotic processing (r ranging from 0.5 to 0.6; p < 0.0001). Significant improvements in performance on retest occurred for the FR LE, RE, total, and diotic conditions (p ranging from 0.05 to 0.0004), the conditions that would be expected to improve with practice if the participant's response strategies are better the second time around. CONCLUSIONS: The addition of a diotic control task-that shares many response demands with the usual dichotic tasks-opens up the possibility of differentiating children who perform below expectations because of poor dichotic processing skills from those who perform poorly because of impaired attention, memory, or other cognitive abilities. The high correlation between dichotic and diotic performance suggests that factors other than dichotic performance play a substantial role in a child's ability to perform a dichotic listening task. This hypothesis is investigated further in the cognitive correlation study that follows in the companion paper (DDdT Study Part 2; Cameron et al, 2016).

Elaboración y validación de una prueba de bisílabos dicóticos en español / Development and validation of a dichotic disyllabic test in Spanish

El propósito de esta investigación es elaborar y obtener indicadores psicométricos para una prueba de bisílabos dicóticos (PBD), de fácil y rápida aplicación, que evalúe el procesamiento auditivo. Esta prueba fue elaborada en la unidad de Audiología de la Escuela de Fonoaudiología de la Universidad de Talca. Se evaluaron 49 sujetos normoyentes. Veintiún sujetos fueron reevaluados para determinar el coeficiente de estabilidad. La PBD mostró un alto valor de consistencia interna (alfa de Cronbach de .86) y una alta confiabilidad test-retest (r = .89; p < .01). Al mismo tiempo se determinó a través de la validez de constructo que la prueba mide la habilidad de escucha dicótica. Los puntajes obtenidos fueron mayores en los sets de 4 estímulos que en los de 6 estímulos. Además se obtuvieron valores mayores en el reconocimiento de palabras por el oído derecho que por el oído izquierdo. Los resultados demuestran la validez del instrumento y su factibilidad de aplicación en población adulta (AU)

The purpose of this study is to develop and obtain the psychometric indicators for a dichotic disyllabic test (DDT) in order to assess auditory processing. This test was developed in the unit of Audiology, School of Audiology at the University of Talca. The study included 49 normal hearing subjects, 21 of whom were re-assessed to determine the reliability coefficient. The DDT showed high test-retest reliability (r = .89; P < .01) and a significant internal consistency value (Cronbach's alpha .86). At the same time, using the construct validity, it was determined that the DDT can be used to measure the ability of dichotic listening. Higher scores were obtained in four stimuli sets than in six stimuli sets. Higher values were obtained in word recognition for the right ear than in the left ear. All these findings suggest that the DDT is valid, and can be applied to obtain normal data for an adult population (AU)

Benchmarks for the Dichotic Sentence Identification test in Brazilian Portuguese for ear and age / Valores de referência para o teste de identificação de sentenças dicóticas em português brasileiro segundo orelha e idade

ABSTRACT INTRODUCTION: Dichotic listening tests should be used in local languages and adapted for the population. OBJECTIVE: Standardize the Brazilian Portuguese version of the Dichotic Sentence Identification test in normal listeners, comparing the performance for age and ear. METHODS: This prospective study included 200 normal listeners divided into four groups according to age: 13-19 years (GI), 20-29 years (GII), 30-39 years (GIII), and 40-49 years (GIV). The Dichotic Sentence Identification was applied in four stages: training, binaural integration and directed sound from right and left. RESULTS: Better results for the right ear were observed in the stages of binaural integration in all assessed groups. There was a negative correlation between age and percentage of correct responses in both ears for free report and training. The worst performance in all stages of the test was observed for the age group 40-49 years old. CONCLUSIONS: Reference values for the Brazilian Portuguese version of the Dichotic Sentence Identification test in normal listeners aged 13-49 years were established according to age, ear, and test stage; they should be used as benchmarks when evaluating individuals with these characteristics.

RESUMO Introdução: Os testes de escuta dicótica devem ser utilizados na língua nativa e adaptados para a população alvo. Objetivo: Estabelecer critérios de referência para o teste DSI em indivíduos normouvintes segundo a orelha, faixa etária e etapa do teste. Método: Estudo prospectivo transversal com 200 indivíduos normouvintes, separados em quatro grupos: 13 a 19 anos (GI), 20 a 29 anos (GII), 30 a 39 anos (GIII) e 40 a 49 anos (GIV). O teste DSI foi aplicado em quatro etapas: Treino, integração binaural, escuta direcionada direita e esquerda. Resultados: Foram observados melhores resultados para a orelha direita nas etapas de integração binaural em todos os grupos avaliados. Houve correlação negativa entre a porcentagem de acertos e a idade, bilateralmente, para as etapas de treino e integração binaural. O pior desempenho, em todas as etapas do teste, foi observado para a faixa etária de 40 a 49 anos de idade. Conclusões: Os valores de referência para a versão em português brasileiro do teste DSI em indivíduos normouvintes de 13 a 49 anos de idade foram estabelecidos segundo a idade, orelha e etapa do teste e devem ser utilizados como padrões de referência na avaliação dos indivíduos com essas características.

Benchmarks for the Dichotic Sentence Identification test in Brazilian Portuguese for ear and age.

INTRODUCTION: Dichotic listening tests should be used in local languages and adapted for the population. OBJECTIVE: Standardize the Brazilian Portuguese version of the Dichotic Sentence Identification test in normal listeners, comparing the performance for age and ear. METHODS: This prospective study included 200 normal listeners divided into four groups according to age: 13-19 years (GI), 20-29 years (GII), 30-39 years (GIII), and 40-49 years (GIV). The Dichotic Sentence Identification was applied in four stages: training, binaural integration and directed sound from right and left. RESULTS: Better results for the right ear were observed in the stages of binaural integration in all assessed groups. There was a negative correlation between age and percentage of correct responses in both ears for free report and training. The worst performance in all stages of the test was observed for the age group 40-49 years old. CONCLUSIONS: Reference values for the Brazilian Portuguese version of the Dichotic Sentence Identification test in normal listeners aged 13-49 years were established according to age, ear, and test stage; they should be used as benchmarks when evaluating individuals with these characteristics.

Factors influencing tests of auditory processing: a perspective on current issues and relevant concerns.

BACKGROUND: Tests of auditory perception, such as those used in the assessment of central auditory processing disorders ([C]APDs), represent a domain in audiological assessment where measurement of this theoretical construct is often confounded by nonauditory abilities due to methodological shortcomings. These confounds include the effects of cognitive variables such as memory and attention and suboptimal testing paradigms, including the use of verbal reproduction as a form of response selection. We argue that these factors need to be controlled more carefully and/or modified so that their impact on tests of auditory and visual perception is only minimal. PURPOSE: To advocate for a stronger theoretical framework than currently exists and to suggest better methodological strategies to improve assessment of auditory processing disorders (APDs). Emphasis is placed on adaptive forced-choice psychophysical methods and the use of matched tasks in multiple sensory modalities to achieve these goals. Together, this approach has potential to improve the construct validity of the diagnosis, enhance and develop theory, and evolve into a preferred method of testing. RESEARCH DESIGN: Examination of methods commonly used in studies of APDs. Where possible, currently used methodology is compared to contemporary psychophysical methods that emphasize computer-controlled forced-choice paradigms. RESULTS: In many cases, the procedures used in studies of APD introduce confounding factors that could be minimized if computer-controlled forced-choice psychophysical methods were utilized. CONCLUSIONS: Ambiguities of interpretation, indeterminate diagnoses, and unwanted confounds can be avoided by minimizing memory and attentional demands on the input end and precluding the use of response-selection strategies that use complex motor processes on the output end. Advocated are the use of computer-controlled forced-choice psychophysical paradigms in combination with matched tasks in multiple sensory modalities to enhance the prospect of obtaining a valid diagnosis.

Monotic versus dichotic multiple-stimulus auditory steady state responses in young children.

In their recent study on infant multiple auditory steady state responses (ASSR), the authors found that ASSR amplitudes unexpectedly decreased when switching from 1-ear stimulation to 2-ear stimulation, a result not present in adults. In addition, residual EEG noise levels increased in the 2-ear condition. In the present study, to determine whether to use 1-ear or 2-ear multiple ASSR Protocols clinically, the authors tested a new group of 19 young children to determine whether these unexpected findings could be replicated. ASSR amplitude and EEG noise were compared for 1-ear (4 stimuli) versus 2-ear (8 stimuli) multiple stimuli presented at 60 dBHL. Results indicated a small but significant decrease in amplitudes going from 1-ear (40.1 nV) to 2-ear (37.9 nV) multiple stimuli. EEG noise was not significantly different between the 2 conditions. Despite small amplitude decreases, the 2-ear stimulus condition was more efficient for infants and young children with normal hearing.

Using different criteria to diagnose (central) auditory processing disorder: how big a difference does it make?

PURPOSE: To quantify how 9 different diagnostic criteria affected potential (central) auditory processing disorder ([C]APD) diagnoses in a large sample of children referred for (central) auditory processing ([C]AP) assessment. METHOD: A file review was conducted on 150 children (94 boys and 56 girls; ages 7.0-15.6 years) with normal peripheral hearing who had completed a (C)AP assessment involving low-pass filtered speech, competing sentences, 2-pair dichotic digits, and frequency patterns with linguistic and nonlinguistic report. Each child was classified as having or not having (C)APD based on 9 different sets of diagnostic criteria drawn from published technical reports, position statements, and selected research. RESULTS: The rates of potential (C)APD diagnosis ranged from 7.3% for the strictest criteria to 96.0% for the most lenient criteria. CONCLUSIONS: Until greater consensus is reached, any diagnosis of (C)APD should be qualified by an explicit statement of the criteria used. Calls to abandon the use of (C)APD as a global label should also be supported.

Dichotic listening performance in young adults using low-pass filtered speech.

BACKGROUND: Assessment of interaural asymmetry (IA) on dichotic listening tests becomes challenging when accuracy on one or both ears are at ceiling. Cognitive task demands are often increased to avoid this situation, raising the possibility that non-auditory-specific processes will further influence IA estimation. PURPOSE: To investigate the utility of low-pass filtered dichotic speech stimuli (dichotic filtered words [DFWs]) as a potential auditory-specific technique for increasing task difficulty in the dichotic listening paradigm. RESEARCH DESIGN: A prospective experimental study investigating differences in IA observed for a group of young adults on three dichotic listening tasks differentiated on the basis of stimulus type (unfiltered words, DFWs) and/or mode of test administration (divided attention [DIV]; directed attention [DIR]). STUDY SAMPLE: Thirty-two adults between 18 and 34 yr of age participated in the study. DATA COLLECTION AND ANALYSIS: Accuracy scores on each ear and normalized values of IA (via laterality index) served as dependent measures evaluated in a repeated-measures ANOVA design. Correlation and regression analyses were carried out to investigate potential relationships between participants' behavioral accuracy to experimental stimuli and the magnitude of observed IA. Behavioral profiles of IA were constructed for each participant. RESULTS: Using a traditional DIV test mode, DFW stimuli produced a significantly larger right-ear advantage (REA) as compared to unfiltered speech. The magnitude of the average REA to DFW stimuli was not statistically different between DIV and DIR test modes for the group. Inspection of individual performances, however, revealed that out of the participants who demonstrated meaningful IA during DIV, approximately half produced the same or greater amount of IA during DIR whereas half showed a relative decrease. Participants' accuracy to left-sided stimuli was most related to the magnitude of observed IA across tasks. CONCLUSIONS: The utility of low-pass filtered speech may be helpful in the evaluation of IA obtained during dichotic testing.

Electrophysiological measurement of binaural beats: effects of primary tone frequency and observer age.

OBJECTIVE: The purpose of this study was to determine the reliability of the electrophysiological binaural beat steady state response as a gauge of temporal fine structure coding, particularly as it relates to the aging auditory system. The hypothesis was that the response would be more robust in a lower, than in a higher, frequency region and in younger, than in older, adults. DESIGN: Two experiments were undertaken. The first measured the 40 Hz binaural beat steady state response elicited by tone pairs in two frequency regions: lower (390 and 430 Hz tone pair) and higher (810 and 850 Hz tone pair). Frequency following responses (FFRs) evoked by the tones were also recorded. Ten young adults with normal hearing participated. The second experiment measured the binaural beat and FFRs in older adults but only in the lower frequency region. Fourteen older adults with relatively normal hearing participated. Response metrics in both experiments included response component signal-to-noise ratio (F statistic) and magnitude-squared coherence. RESULTS: Experiment 1 showed that FFRs were elicited in both frequency regions but were more robust in the lower frequency region. Binaural beat responses elicited by the lower frequency pair of tones showed greater amplitude fluctuation within a participant than the respective FFRs. Experiment 2 showed that older adults exhibited similar FFRs to younger adults, but proportionally fewer older participants showed binaural beat responses. Age differences in onset responses were also observed. CONCLUSIONS: The lower prevalence of the binaural beat response in older adults, despite the presence of FFRs, provides tentative support for the sensitivity of this measure to age-related deficits in temporal processing. However, the lability of the binaural beat response advocates caution in its use as an objective measure of fine structure coding.

Performance of normal adults and children on central auditory diagnostic tests and their corresponding visual analogs.

BACKGROUND: It has been suggested that, in order to validate a diagnosis of (C)APD (central auditory processing disorder), testing using direct cross-modal analogs should be performed to demonstrate that deficits exist solely or primarily in the auditory modality (McFarland and Cacace, 1995; Cacace and McFarland, 2005). This modality-specific viewpoint is controversial and not universally accepted (American Speech-Language-Hearing Association [ASHA], 2005; Musiek et al, 2005). Further, no such analogs have been developed to date, and neither the feasibility of such testing in normally functioning individuals nor the concurrent validity of cross-modal analogs has been established. PURPOSE: The purpose of this study was to investigate the feasibility of cross-modal testing by examining the performance of normal adults and children on four tests of central auditory function and their corresponding visual analogs. In addition, this study investigated the degree to which concurrent validity of auditory and visual versions of these tests could be demonstrated. RESEARCH DESIGN: An experimental repeated measures design was employed. STUDY SAMPLE: Participants consisted of two groups (adults, n=10; children, n=10) with normal and symmetrical hearing sensitivity, normal or corrected-to-normal visual acuity, and no family or personal history of auditory/otologic, language, learning, neurologic, or related disorders. DATA COLLECTION AND ANALYSIS: Visual analogs of four tests in common clinical use for the diagnosis of (C)APD were developed (Dichotic Digits [Musiek, 1983]; Frequency Patterns [Pinheiro and Ptacek, 1971]; Duration Patterns [Pinheiro and Musiek, 1985]; and the Random Gap Detection Test [RGDT; Keith, 2000]). Participants underwent two 1 hr test sessions separated by at least 1 wk. Order of sessions (auditory, visual) and tests within each session were counterbalanced across participants. ANOVAs (analyses of variance) were used to examine effects of group, modality, and laterality (for the Dichotic/Dichoptic Digits tests) or response condition (for the auditory and visual Frequency Patterns and Duration Patterns tests). Pearson product-moment correlations were used to investigate relationships between auditory and visual performance. RESULTS: Adults performed significantly better than children on the Dichotic/Dichoptic Digits tests. Results also revealed a significant effect of modality, with auditory better than visual, and a significant modality×laterality interaction, with a right-ear advantage seen for the auditory task and a left-visual-field advantage seen for the visual task. For the Frequency Patterns test and its visual analog, results revealed a significant modality×response condition interaction, with humming better than labeling for the auditory version but the reversed effect for the visual version. For Duration Patterns testing, visual performance was significantly poorer than auditory performance. Due to poor test-retest reliability and ceiling effects for the auditory and visual gap-detection tasks, analyses could not be performed. No cross-modal correlations were observed for any test. CONCLUSIONS: Results demonstrated that cross-modal testing is at least feasible using easily accessible computer hardware and software. The lack of any cross-modal correlations suggests independent processing mechanisms for auditory and visual versions of each task. Examination of performance in individuals with central auditory and pan-sensory disorders is needed to determine the utility of cross-modal analogs in the differential diagnosis of (C)APD.

[Polish language dychotomic tests for speech audiometry Part 2: A study of people with normal hearing from various age groups]. / Testy utrudnione w audiometrii mowy dla jezyka polskiego (czesc II). Badania osób z prawidlowym sluchem w róznych grupach wiekowych.

INTRODUCTION: Evaluation of the objective results in the clinical examination of central auditory disorders requires the use of reliable language tests which provide the means for the estimation of patients' audio-verbal communicative skills. MATERIALS AND METHODS: The authors present a new set of more difficult language tests in Polish, including a filtered speech test, numeral and verbal dichotic tests and the normal Calearo test. The tests were evaluated on a group of people with good hearing from various age groups. CONCLUSIONS: The presented tests are the only existing ones created for the Polish language which expand the diagnostic possibilities in the case of central auditory processing disorders. It was found that there is a right ear predominance in dichotic tests, which grows together with the patient's age. This observation can be very beneficial in practice, allowing for hearing aids to be better fitted.

Dichotic word recognition in young and older adults.

Dichotic word recognition was evaluated in free-recall, directed-attention right, and directed-attention left response conditions. All participants were right-handed and included a group of young adults with normal hearing and two groups of older adults with sensorineural hearing loss. Dichotic word recognition performance was best for young adults and decreased for each older group. A right-ear advantage (REA) was observed for all groups. REAs observed in the older groups were larger than those for the young adults, resulting from a greater deficit in dichotic word recognition performance for words presented to the left ear. A subset of older adults exhibited few to no responses (< or = 3/100) for the left ear for all response conditions, which may relate to a compromise in auditory processing. The results support an age-related disadvantage in recognition performance for dichotic stimuli presented to the left ear not entirely accounted for by differences in hearing sensitivity between subject groups.

Development and standardization of single and double dichotic digit tests in the Malay language.

Single and double dichotic digit tests in Malay language were developed and standardized as an initial attempt to incorporate tests of auditory processing within the scope of audiology practice in Malaysia. Normative data under free recall, directed right-ear first, and directed left-ear first listening conditions were determined using 120 Malay children between the ages of 6 and 11 years old with normal hearing and normal academic performance. Test-retest reliability was assessed in 15 of the study subjects. In general, the double dichotic digit test produced greater differences in scores between age groups, and a greater right-ear advantage than the single dichotic digit test. In addition, the double dichotic digit test also had higher test-retest reliability. These findings suggest the double dichotic digit test is more clinically applicable.

[Speech tests: application in individuals with noise induced hearing loss]. / Testes de fala: aplicação em portadores de perda auditiva induzida por ruído.

BACKGROUND: Speech intelligibility. AIM: To evaluate speech recognition in individuals with noise induced hearing loss (NIHL). METHOD: 79 adults were divided in two groups: a control group with 39 individuals with hearing limits up to 25 dB, and a research group with 40 individuals with audiometric configuration and occupational history suggesting NIHL. The following tests were used with all individuals: Speech Recognition Test, dichotic test Staggered Spondaic Word (SSW) and Speech in Noise Test (signal/noise ratio of +5 and -5 dB with ipsilateral white noise). RESULTS: The Speech Recognition Test and the SSW are not or little useful to discriminate between individuals with NIHL and those with normal hearing. CONCLUSION: The Speech in Noise Test can be sensitive in the identification of the hearing alterations presented by individuals with NIHL.

Testes de fala: aplicação em portadores de perda auditiva induzida por ruído / Speech tests: application in individuals with noise induced hearing loss

Tema: inteligibilidade de fala. Objetivo: avaliar o reconhecimento de fala de portadores de Perda Auditiva Induzida por Ruído (PAIR). Método: participaram deste estudo 79 indivíduos adultos divididos em dois grupos: o grupo-controle, composto por 39 pessoas com limiares auditivos até 25dB, e o grupo-pesquisa com 40 portadores de traçado audiométrico e história ocupacional de PAIR. Em todos, foram aplicados os testes: Índice Percentual de Reconhecimento de Fala (IPRF), teste de tarefa dicótica Staggered Spondaic Word (SSW) e Teste de Fala com Ruído (nas relações sinal/ruído +5 e -5dB, com ruído branco ipsilateral). Resultados: o IPRF e o SSW são nada ou pouco úteis para discriminar portadores de PAIR de normo-ouvintes. Conclusão: o Teste de Fala com Ruído pode ser sensível na identificação de alterações auditivas em portadores de PAIR.

Toward solving the inferential problem in laterality research: effects of increased reliability on the validity of the dichotic listening right-ear advantage.

As noted by Satz, the prevalence of lateralized language in the general population is underestimated substantially by the proportion of people who show the typical asymmetry on a laterality task. In a series of two dichotic listening experiments with a total of 171 right-handers and 170 left-handers, we tested the hypothesis that increased reliability of measurement will lead to increased classification accuracy. Experiment 1 showed that neither the frequency nor magnitude of the right-ear advantage (REA) for fused rhyming words increased as the number of trials increased from 120 to 480. Ear-difference scores were highly reliable (r = .85), even when based on 120 trials. Experiment 2, which involved lists of dichotic word pairs, yielded similar results. Even though retest reliability of the ear-difference score for 132 word pairs was only .45, neither the incidence nor strength of the REA increased significantly when the number of pairs was increased to 528. The results indicate that the poor classification accuracy of dichotic listening tasks cannot be attributed to unreliability.

Test-retest performance for the consonant-vowel dichotic listening test with and without attentional manipulations.

The present work aimed to replicate Hugdahl and Hammar's (1997) study on the reliability of dichotic listening under divided or focused attention conditions. With the same consonant-vowel syllable dichotic listening procedure, 16 subjects were tested twice, 2 weeks apart. The design included a condition without attentional instructions (nonforced) and two conditions with the instruction to attend either to the right- or the left-ear input. The results showed a significant correlation coefficient of.82 for the standard nonforced condition, indicating temporal stability for the ear advantages. There were also high correlation coefficients for the focused attention conditions (.77 and.76), although the subjects performed the attentional instructions more accurately in session two.

Test-retest reliability for the consonant-vowel syllables dichotic listening paradigm.

The present study compared test-retest reliability for dichotic listening (DL) performance to consonant-vowel (CV) syllables under three different attentional instructions. Previous studies of reliability in dichotic listening have shown great variability which most likely reflects the large variations in stimuli, procedures, and techniques used in the different studies. Sixteen subjects were tested twice, 2 weeks apart, with the same dichotic listening procedure, including a divided attention condition and two focused attention conditions on each test occasion. The results showed test-retest correlations ranging from .61 to .86 for the three attentional conditions, with the smallest correlation coefficient for the divided attention condition.