Performance of Toddlers, Children and Young Adults Using Unilateral or Bilateral Cochlear Implants on a Left versus Right Loudspeaker Identification Task

Abstract

Thirty-six participants with bilateral cochlear implants aged 1–19 years completed a left versus right loudspeaker identification task. The majority performed at chance in the unilateral condition (n = 24) and significantly above chance in the bilateral condition (n = 28). Cluster analysis identified three groups; one group performed above chance in both conditions and was older at second implant and older at testing, with longer delay between implants. There were no such differences between the group performing at chance in both conditions and the group which scored highly in the bilateral condition only, thus demonstrating a bilateral benefit. Unilateral, but not bilateral, scores were correlated with age at second and at first implant, time between implants, and age at testing. Bilateral benefit was negatively correlated with age at second implant, time between implants and age at testing. Co-linearity made it difficult to isolate the relationships with demographic factors, though age at testing may have had the most influence on unilateral scores. Spatial hearing skills with bilateral implants cannot be predicted for individuals.

Everyday Listening Performance of Children Before and After Receiving a Second Cochlear Implant

“…The degree of difference between the median group rating in the UniCI(+HA) versus the BiCIs conditions ranged from 2.5 to 6; this was generally greater than the 0.75 to 2.5 difference for the speech perception section. These results are consistent with the objective evidence of improved lateralisation and localisation skills (Galvin et al, 2011;Grieco-Calub & Litovsky, 2010;Lovett et al, 2010;Van Deun et al, 2009b) and with the subjective reports of improved localization in daily life for children using BiCIs (Redfern & McKinley, 2011;Sparreboom et al, 2012b;Scherf et al, 2009). Improved performance in the types of scenarios described in the spatial section will benefit communication in daily life, and will also provide valuable functional benefits related to convenience and safety.…”

“…The variation in results across individuals is consistent with the variation in objectively measured bilateral benefit across many studies evaluating spatial hearing, speech perception, and listening effort (see, for example, Galvin et al, 2011;Sparreboom et al, 2010;van Deun et al, 2009a).…”

“…This provides a clear advantage in a group conversation as the speakers will be in various locations relative to the listener. The improvement in spatial hearing ability demonstrated for many children using BiCIs (Beijen et al, 2007;Galvin et al, 2011;Litovsky, 2011;Murphy et al, 2011) will help the listener to locate the speaker in a group conversation. Directing visual attention towards the speaker is socially appropriate, but also gives access to visual cues, such as lip movements and body language, and may provide an improved signal-to-noise ratio.…”

“…In many countries an increasing proportion of children with severe-profound hearing loss are receiving bilateral cochlear implants (CIs). There is objective evidence in the literature that performance with bilateral CIs is typically superior to that with a unilateral CI on tests of spatial hearing (Galvin et al, 2011;Grieco-Calub & Litovsky, 2010;Lovett et al, 2010) and of speech perception, particularly in noise (Galvin et al, 2007;Lovett et al, 2010;Sparreboom et al, 2010;van Deun et al, 2010). There is also objective evidence that listening effort for a dual-task paradigm is reduced for some individuals when using bilateral CIs (Hughes & Galvin, 2013).…”

Achievement of early clinical milestones and long-term functional outcomes for children and young adults with bilateral cochlear implants

“…Objective assessments of spatial hearing, speech perception, and listening effort have been conducted; see, for example, Galvin et al (2011), Galvin et al (2008), and Hughes and Galvin (2013). Subjective information has also been collected, both to document early post-operative progress in adapting to BiCIs, and to document functional outcomes at a longer-term point at which such outcomes were likely to be stable.…”