Weighting of cues for fricative place of articulation perception by children wearing cochlear implants

Abstract

Abstract

Objective: To determine how children wearing cochlear implants weight cues for fricative perception compared to age-matched children with normal hearing. Design: Two seven-step continua of synthetic CV syllables were constructed, with frication pole varied from /s/ to /∫/ within the continuum, and appropriate formant transition values varied across continua. Relative weights applied to the frication, transition, and interaction cues were determined. Study Sample: Ten 5–7-year-old children with normal hearing and ten 5–8-year-old children wearing cochlear implants participated. Results: Both groups of children gave more perceptual weight to the frication spectral cue than to the formant transition cue. Children with normal hearing gave small but significant weight to formant transitions, but the children wearing cochlear implants did not. The degree of cue interaction was significant for children with normal hearing but was not for children wearing cochlear implants. Conclusions: Children wearing a cochlear implant use similar cue-weighting strategies as normal listeners (i.e. all apply more weight to the frication noise than to the transition cue), but may have limitations in processing formant transitions and in cue interaction.

Sumario

Objetivo: Determinar el valor que los niños que usan implante coclear le dan a las claves para percibir las fricativas, en comparación con niños normoyentes de la misma edad. Diseño: Se construyeron dos continuos de siete pasos consistentes en sílabas sintéticas CV, con polo fricativo que variaba de /s/ a /∫/ dentro del continuo, y con valores de formato de transición que variaban a través del continuo. Se determinaron los pesos relativos aplicados a la fricación, la transición y la interacción de claves. Muestra: Participaron diez niños de 5 a 7 años de edad con audición normal y diez niños de 5 a 8 años de edad con implante coclear. Resultados: Ambos grupos de niños dieron un mayor valor perceptual a las claves del espectro fricativo que a las claves de transición de los formantes. Los niños normoyentes dieron un valor pequeño pero significativo a las transiciones de las formantes; no así los niños con implante coclear. Conclusiones: los niños con implante coclear utilizan estrategias similares para valorar las claves que los niños normoyentes (i.e. todos dan más valor al sonido fricativo que a la clave de transición, pero tienen limitaciones para procesar las transiciones de las formante en la interacción de claves.

Key Words::

• Speech
• consonant perception
• cochlear implants
• normal auditory system
• hearing loss

Acknowledgements

This work was presented at the Spring 2006 meeting of the American Auditory Society, thanks to a Mentored National Institutes of Health grant awarded to the second author. Support for this work was supplied in part by a grant awarded to the second author from the American Academy of Audiology Foundation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.