Intra-word variability in children acquiring Finnish

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Wetteri auditorium (IT115), Linnanmaa, University of Oulu, Zoom link:

Topic of the dissertation

Intra-word variability in children acquiring Finnish

Doctoral candidate

Licentiate of Philosophy Anna-Leena Martikainen

Faculty and unit

University of Oulu Graduate School, Faculty of Humanities, Child Language Research Center

Subject of study



Professor Minna Laakso, University of Helsinki


Professor Sari Kunnari, University of Oulu

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Intra-word variability in children acquiring Finnish

In typical speech development, there is a phase when a child might produce a word in different ways on different occasions. This characteristic of speech, called intra-word variability, has not been studied among children acquiring Finnish. Its trajectory in typical speech development and role in identifying impaired speech is hence unknown in Finnish.

This thesis investigated intra-word variability in typically developing 3- to 6-year-old Finnish children (TD) and children with speech sound disorder (SSD) aged between 3 and 5. Furthermore, a possible association between highly variable speech with no correct word forms and the quality of underlying phonological representations and speech production skills was examined. Intra-word variability was assessed by a picture-naming task. The phonological representations were assessed by vocabulary, phonological awareness, and nonword repetition (NWR) measures, and speech production skills by measures derived from a spontaneous speech and picture-naming sample, and a syllable repetition task.

In the TD children, intra-word accuracy and consistency were already relatively high at the age of three, and variable responses without any correct word form were rare. The speech production of the children with SSD was more inaccurate and inconsistent than their TD peers’. In the TD group, in addition to poor NWR, poor phonological awareness and speech production skills were associated with highly variable speech, but not in all measures. Among the children with SSD, highly variable speech was associated with poor receptive vocabulary knowledge, NWR, and speech production skills.

The results provide evidence that highly variable speech with no correct word forms may already signal impaired speech development from the age of 3 onwards. Increased speech inconsistency among children with SSD appears to be associated with both phonological representations and the motor components of speech production. A sufficiently comprehensive assessment protocol for children with SSD is thus warranted to reveal their individual skill profiles and make appropriate clinical management decisions.
Last updated: 1.3.2023