Effect of gap detection threshold on consistency of speech in children with speech sound disorder

The present study examined the relationship between gap detection threshold and speech error consistency in children with speech sound disorder.

The participants were children five to six years of age who were categorized into three groups of typical speech, consistent speech disorder (CSD) and inconsistent speech disorder (ISD).The phonetic gap detection threshold test was used for this study, which is a valid test comprised six syllables with inter-stimulus intervals between 20-300ms. The participants were asked to listen to the recorded stimuli three times and indicate whether they heard one or two sounds.

There was no significant difference between the typical and CSD groups (p=0.55), but there were significant differences in performance between the ISD and CSD groups and the ISD and typical groups (p=0.00). The ISD group discriminated between speech sounds at a higher threshold.

Children with inconsistent speech errors could not distinguish speech sounds during time-limited phonetic discrimination. It is suggested that inconsistency in speech is a representation of inconsistency in auditory perception, which causes by high gap detection threshold.