Phoneme Isolation

This test measures phoneme awareness (that is, speech sound manipulation) skills, in particular of nonwords differing in levels of phonological complexity. Targeted phonemes in this test are initial consonants (onsets) and final consonants (codas).

Age range

Phoneme Isolation is conceptually less difficult than Phoneme Deletion and therefore is suitable for children in Reception and Year 1, and for older children who have suspected or confirmed phonological and/or literacy difficulties. 

Scoring: accuracy

Accuracy only is measured.  Where children have reached mastery ( ≥ 80%) in accuracy on both Onsets and Codas in this test, the more complex test of Phoneme Deletion should be considered, in which both accuracy and time are measured. 


Grade norms are currently available for Reception Year and Year 1.

Materials for administration

Recording device

Phoneme Isolation Task Instructions

Phoneme Isolation Task Score Sheet

Please ensure you are using the most up-to-date test version:

Test Version: 4

Norm Version: 1

Updated: 23.02.2021

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