Developmental effects and spatial hearing in young children with normal-hearing sensitivity

Previous research suggests that young children have significant difficulty recognizing speech in the presence of background noise as compared with older children and adults. However, limited research exists that examines the developmental effects of speech recognition in noise in separate age groups of young children, especially in a classroom setting. The lack of research may relate to the limited number of tests with multiple, equally intelligible lists in noise that are also appropriate for young children. As a result, the goals of the present study include investigating (1) effects of age and (2) benefits of spatial separation of speech and noise sources on the speech recognition in noise performance of young children with normal-hearing sensitivity. A secondary goal of the study was to establish the validity and reliability of the Phrases in Noise Test (PINT) for assessing the 50% correct speech-in-noise threshold of young children.

The investigators used a two-way repeated measures design to examine the main effects of age and spatial separation. Sixty-eight children in separate groups of 3-, 4-, 5-, and 6-year-olds and 17 adults completed two speech-recognition conditions with (1) speech and noise from the same loudspeaker at 0-degree azimuth (S0/N0) and (2) speech and noise from separate loudspeakers at 0- and 180-degree azimuth (S0/N180). Recruiting sites included local preschools and school districts for children and a university for adults.

The results of this investigation suggest that younger children (<4 years of age) have significantly poorer speech-in-noise thresholds than older children and adults, and 4- and 5-year-old children also have significantly poorer performance than adults when speech and noise are presented from the same spatial location. All participants obtained significant spatial release from masking. On a parent and teacher screening questionnaire to assess educational risk, five of 12 children with at-risk behaviors had poor speech-in-noise thresholds relative to their peers. When two lists of the PINT are used, the test seems to be a valid and reliable measure for assessing young children's speech-in-noise thresholds.

Young children exhibit significantly poorer speech recognition than do older children and adults in a classroom, especially when speech and noise are presented from the same location. Given the poor acoustics of typical classrooms, and the earlier age at which many children are educated, special modifications to classrooms may be necessary to improve listening through acoustic modifications or classroom amplification. A combination of a parent or teacher questionnaire and the PINT may be helpful in identifying children who are at risk for educational delays and listening difficulties in classrooms with typically poor acoustics.