Acoustic, aerodynamic, and perceptual analyses of the voice of cochlear-implanted children

The purposes of this study were to compare, from an acoustic approach, the voice of cochlear-implanted children and the one of deaf children using conventional hearing aids (HA) to a control group; to characterize, from an aerodynamic approach, the voice of congenital/prelingual profound deaf children wearing cochlear implants for at least 3 years and implanted before 3 years old; and to classify, from a perceptual approach, the voice of implanted children, of fitted children with conventional HA, and of normal hearing (NH) children as "normal or dysphonic voices."

We analyzed 78 voices of children aged 5-13 years using EVA 2 workstation: 38 children with NH, 40 deaf children wearing HA and cochlear implants for at least 3 years and being implanted before 3 years old. Acoustic parameters were measured from a sustained vowel /a/ and speech production and aerodynamic parameters from a set of 10 syllables /pa/. Perceptive assessment was performed by a jury of experienced listeners using G component of Hirano's GRBAS (Grade, Rough, Breathy, Asthenic, Strained) scale.

Some acoustic parameters differ significantly between NH children and deaf children's groups with HA and cochlear implants, whereas other parameters are similar between control and cochlear-implanted groups. Analysis of aerodynamic parameters indicates that the phonatory physiological behavior of the implanted group is following an evolution within the norm. Finally, results of perceptual analysis reveal that the implanted group's voice samples can be classified in the first two grades (G0=9, G1=11, n=20) according to the G component (overall dysphonia) of the GRBAS scale.

Cochlear implants may improve the majority of acoustic parameters of the voice better than HA for deaf children. Glottal and laryngeal efficiencies were significantly increased with the chronological age and the time of wearing an implant. Results suggest that voices of implanted children in our study do not reveal vocal characteristics traditionally used to determine the dysphonic voice.