Infants' and Adults' Use of Temporal Cues in Consonant Discrimination.

This is a laboratory study of typical infants and adults, not a clinical trial, so it cannot show how therapy should change for patients. The sounds were vocoded and had their natural pitch-related frequency modulation cues removed, so they are not normal speech. The slow-cue test always came after the fast-plus-slow test, so practice or confusion could have affected the results, although reminder trials suggested that failures were not simply due to tiredness or boredom. Each participant was tested in only one consonant contrast and in either quiet or noise, so comparisons across conditions are between different groups. Adults were not told that the sounds were speech, and few believed they were speech, which may have affected adult performance, especially in noise. Six additional infants were excluded because they were tired, hungry, or fussy, and one infant was excluded because of the tympanometric screen, so the tested group may not represent all infants. The participants were 3-month-olds and normal-hearing adults, so it does not address older children or people with hearing loss or speech-language disorders.

The authors declared that they have no conflict of interest.

Do not conclude that infants cannot use slow temporal cues for speech discrimination. Some infants passed the slow-cue condition, and the study used distorted consonant sounds in a laboratory task, not everyday speech.