首页   按字顺浏览 期刊浏览 卷期浏览 Development of auditory information integration abilities
Development of auditory information integration abilities

 

作者: Prudence Allen,   James Nelles,  

 

期刊: The Journal of the Acoustical Society of America  (AIP Available online 1996)
卷期: Volume 100, issue 2  

页码: 1043-1051

 

ISSN:0001-4966

 

年代: 1996

 

DOI:10.1121/1.416290

 

出版商: Acoustical Society of America

 

关键词: CHILDREN;ACOUSTIC TESTING;IDENTIFICATION SYSTEMS;FREQUENCY SELECTION;NOISE;AGE DEPENDENCE

 

数据来源: AIP

 

摘要:

The ability of normal‐hearing children (aged 4 through 7 years) and adults to integrate information was measured in an auditory sample discrimination task. On each trial a pair of tonal sequences was played whose component frequencies were randomly drawn from two equal‐variance, Gaussian distributions with different means. The listeners task was to identify the sequence drawn from the distribution with the higher mean frequency. Performance was first evaluated as a function of the number of components in each sequence. Results showed that discrimination accuracy improved with increasing age until age 7, at which time performance was adult‐like. The 7‐year‐olds and the adults discriminated the sequences with increasing accuracy as the sequence length was increased, but the 4‐ to 6‐year‐old listeners, as a group, did not. Data were fitted with a model with two free parameters, one representing resolution of the components and presumed to reflect peripheral processing, and another representing central noise added to the decision process after the component information is combined [R. Lutfi, J. Acoust. Soc. Am.86, 934–944 (1989)]. On average, both parameters showed gradual changes as age increased, with adult‐like values by 7 years of age. Individual data however suggest that the changes in central noise with age may be less gradual than the changes in peripheral resolution. In a second condition, increases in component duration produced improved performance for the 7‐year‐olds and the adults, while that of the younger listeners remained the same. Fitted parameters suggested improvements in component resolution for the older children, with no changes in central noise levels. In a third condition, reducing the overlap in the distributions improved performance for only a few of several younger children. This improvement was attributable to lower levels of central noise. Overall, these results suggest that with increasing age children are better able to discriminate between sounds that are variable and have overlapping acoustic characteristics. This age‐related improvement may be attributed both to improvements in the ability to resolve the components and to reductions in central noise.

 

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