A child who is participating in the study will be assessed at 1, 2, and 3 years of age using standardised speech and language tests as well as audiological evaluations.

Speech and language tests

PLS- Preschool Language Scale

The Preschool Language Scale (PLS) is used to assess children's understanding and use of English. The test is administered to monitor the development of ‘auditory comprehension'; and ‘expressive communication’ from birth through 6 years 11 months of age. The PLS tests the child’s understanding of spoken language (Auditory Comprehension) and their use of spoken language (Expressive Communication). The PLS uses parental input, specific testing toys (such as a teddy bear and cups/spoons) as well as a book with colourful pictures in order to test the child’s language. The PLS scores also give teachers information about the child's language development that is useful for planning educational programs.

DEAP- Diagnostic Evaluation of Articulation and Phonology

The DEAP is a test that assesses children’s speech and is used with children from the age of 3yrs. The subtest used to assess children in the CUHL study examines how children say all of the sounds in English in isolated words. The DEAP also looks at the accuracy of the child’s speech by calculating the number of sounds the child produced correctly out of all the sounds in the test. There are three measures used – percentage consonants correct (PCC), percentage vowels correct (PVC) and percentage phonemes correct (PPC). The DEAP has been administered to a large number of Australian children so it is possible to view the child’s performance in relation to his peers.

PPVT-4- Peabody Picture Vocabulary Test

The PPVT-4 is a test of receptive English vocabulary that requires the child to point to the picture which demonstrates the word they hear. For example the examiner says “Show me baby” and the child needs to look at the four pictures on the page and point to the picture of the baby. The PPVT-4 can be used with children from age two and a half through to adults aged over 90yrs. For this reason there is a wide variety of vocabulary. The test starts with simple items such as ‘sock’ and ends with more difficult items such as ‘pedagogue’ and ‘laciniated’, however the PPVT-4 is designed so that the child is only given the test to just above their developmental level.


This test is optional for the families participating in the study. The LENA Pro system is an audio-recording device that allows researchers to collect and analyse speech and language development in babies between 2 and 48 months. LENA Pro is being used at more than 200 universities, hospitals and other research institutions around the world. This system allows researchers to analyse the number of words spoken to the child, estimate the number of adult-child conversational interactions as well as examine the kinds of sounds the child is hearing i.e. TV, voices or noise.