Reaching for sound measures: an ecologically valid estimate of spatial hearing in 2- to 3-year-old children with bilateral cochlear implants.

HYPOTHESIS A novel reaching for sound (RFS) methodology can yield a high level of spatial hearing ability in 2- to 3-year-old children with normal hearing and with bilateral cochlear implants (BiCIs). BACKGROUND A growing number of children who are deaf are receiving BiCIs at a young age. Their spatial hearing abilities are emerging but highly variable within the population. Our novel reaching for sound method uses an ecologically valid approach that engages children and maintains their motivation. The present work was aimed at using the novel RFS method to evaluate spatial hearing in 2- to 3-year-olds with normal hearing and with BiCIs. METHODS Six children with BiCIs and 15 children with NH, ages 2 to 3 years participated. In the BiCI group, testing was performed in bilateral or single CI (unilateral) conditions. Loudspeakers were separated by ± 60, ± 45, ± 30, or ± 15 degrees. On each trial, a small toy was hidden behind one of the loudspeakers, and the child's task was to reach through a hole in the curtain above the loudspeaker, to indicate source location. Children were reinforced for correct responses. At each angle, the ability of the child to reach criterion of 80% or greater correct was assessed. RESULTS All BiCI users reached criterion at all angles tested in the bilateral condition; however, performance was poorer when using a single CI. Of the 15 NH children, 13 were able to perform the task accurately and reached criterion at all angles. CONCLUSION Spatial hearing skills studied with the RFS method revealed novel findings regarding the emergence of sound localization in very young BiCI users.