A test battery (IMAP) for performing an in-depth assessment of auditory and cognitive abilities contributing to listening skills is described. It is quick to administer, child-friendly and free from linguistic confounds. Stimulus generation and protocol management are controlled via a software platform (IHR-STAR) to ensure replicable procedures.
The ability to hear is only the first step towards making sense of the range of information contained in an auditory signal. Of equal importance are the abilities to extract and use the information encoded in the auditory signal. We refer to these as listening skills (or auditory processing AP). Deficits in these skills are associated with delayed language and literacy development, though the nature of the relevant deficits and their causal connection with these delays is hotly debated.
When a child is referred to a health professional with normal hearing and unexplained difficulties in listening, or associated delays in language or literacy development, they should ideally be assessed with a combination of psychoacoustic (AP) tests, suitable for children and for use in a clinic, together with cognitive tests to measure attention, working memory, IQ, and language skills. Such a detailed examination needs to be relatively short and within the technical capability of any suitably qualified professional. Current tests for the presence of AP deficits tend to be poorly constructed and inadequately validated within the normal population. They have little or no reference to the presenting symptoms of the child, and typically include a linguistic component. Poor performance may thus reflect problems with language rather than with AP. To assist in the assessment of children with listening difficulties, pediatric audiologists need a single, standardized child-appropriate test battery based on the use of language-free stimuli.
We present the IMAP test battery which was developed at the MRC Institute of Hearing Research to supplement tests currently used to investigate cases of suspected AP deficits. IMAP assesses a range of relevant auditory and cognitive skills and takes about one hour to complete. It has been standardized in 1500 normally-hearing children from across the UK, aged 6-11 years. Since its development, it has been successfully used in a number of large scale studies both in the UK and the USA. IMAP provides measures for separating out sensory from cognitive contributions to hearing. It further limits confounds due to procedural effects by presenting tests in a child-friendly game-format. Stimulus-generation, management of test protocols and control of test presentation is mediated by the IHR-STAR software platform. This provides a standardized methodology for a range of applications and ensures replicable procedures across testers. IHR-STAR provides a flexible, user-programmable environment that currently has additional applications for hearing screening, mapping cochlear implant electrodes, and academic research or teaching.
Good listening skills (i.e., AP) are believed to provide a firm basis for the further development of important cognitive skills such as speech, language and literacy1-3. Yet, there has been much debate about the nature of the relevant listening skills, if indeed they are relevant, necessary, or sufficient for causing difficulties in language or literacy4. Part of the problem for understanding the role of listening skills in cognitive development reflects the fact that children are very variable in their ability to perform taxing and, from their perspective, rather dull tests of AP (‘psychophysical tasks’). This makes it difficult to separate out procedural effects, such as boredom, from more fundamental variations in functioning of central auditory processing pathways. As we have detailed in our protocol, the IMAP test battery was carefully designed to minimize confounds arising from issues associated with the test procedure.
In Figure 4, we provide comparisons of performance of two children on a backward masking task. Because IMAP minimizes procedural confounds, and children cannot begin the test until they demonstrate they understand it, we can be confident in ascribing the different performances of these two children to test-specific factors for each child. The inclusion in the IMAP battery of paired AP tests5 and a range of cognitive tests further permits us to explore the reasons for this individual variation. We recently completed a UK population-based study using IMAP5. This showed how response variability and performance on tests tapping cognitive skills, such as attention, explained most of the variation in performance on the AP tests. The population-based study also provided us with standardized measures of performance. These measures are necessary to assess individual performance in the clinic. They are currently being used in a study investigating heritability of listening skills in identical and fraternal twins. This latter study will permit us to develop standardized measures suitable for use with children in the US.
Though currently child-focused in design, IMAP can also be used with adults, as demonstrated by Strait et al.,6 who found an important contribution from cognitive skills honed by musical training to the development of auditory processing skills.
The authors have nothing to disclose.
The research and development leading to the IMAP-test battery and IHR-STAR was funded by the Medical Research Council (MRC) and a grant from the Oticon Foundation. Thanks go to Lorna Halliday, Sally Hind and Alison Riley, who provided help in the planning stages of the work and Sonja Ratib and team for testing the IMAP test battery during the large population-based study or auditory processing. IHR technical and support staff provided invaluable assistance with the project – we particularly acknowledge the contributions of Tim Folkard, Victor Chilekwa, Dave Bullock and John Chambers.
Material Name | Tipo | Company | Catalogue Number | Comment |
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IHR-STAR2 | presentation platform | |||
IHR-Runner program | for pseudo-random order of presentation of tests | |||
Laptop | Processor speed – 2 GigaHz; RAM – 1 Gigabyte; Operating system – Windows XP |
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USB IHR-audio-device | to control sound presentation level and spectrum content | |||
Response button box | ||||
Headphones | Sennheiser | HD25-1 |