Cochlear Implants or Hearing Aids: Speech Perception, Language, and Executive Function Outcomes

We aimed to determine whether children with severe hearing loss (HL) who use hearing aids (HAs) may experience added value in the perception of speech, language development, and executive function (EF) compared to children who are hard of hearing (HH) or children who are deaf and who use cochlear implants (CIs) and would benefit from CIs over HAs. The results contribute to the ongoing debate concerning CI criteria. We addressed the following research question to achieve this aim: Do children who are HH or deaf with CIs perform better than children with severe HL with HAs with respect to auditory speech perception, and receptive vocabulary and/or EF?

We compared two groups of children with severe HL, profound HL or deafness, with CIs or HAs, matched for gender, test age (range, 8 to 15 years), socioeconomic status, and nonverbal intelligence quotient. Forty-three children had CIs (pure-tone average at 2000 and 4000 Hz >85 dB HL), and 27 children had HAs (mean pure-tone average: 69 dB HL). We measured speech perception at the conversational level (65 dB SPL) and the soft speech perception level (45 dB SPL). We established receptive vocabulary using the Peabody Picture Vocabulary Test-III-NL. We tested EF using the Delis Kaplan Executive Function System battery and the Dutch Rey Auditory Verbal Learning Test. We employed the Mann-Whitney U test to compare data between the CI and HA groups. We used Chi-square goodness of fit tests to contrast the CI and HA group distributions with the norm data of children who are typically developing (TD). We harnessed Kendall's Tau-b to investigate relationships between the study variables.

Both groups of children, with CIs and Has, obtained ceiling scores for perception of speech on a conversational level. However, the HA group exhibited significantly lower perception on a soft speech level scores (68 %) than the CI group (87%). No difference was present between the receptive vocabulary distributions of the CI and HA groups. The median receptive vocabulary standard scores for both groups were well within the normal range (CI group: 93; HA group: 96). In addition, we did not find any difference in EF between the CI and HA groups. For planning and verbal memory, the distributions of observed scores for children with CIs were different from the expected distributions of children who are TD. In both groups, a large proportion of children obtained below-average scores for planning (CI: 44%; HA: 33%) and for long-term verbal memory (CI: 44%; HA: 35%). In the HA group, perception at a soft speech level was associated with receptive vocabulary and planning. In the CI group, we did not find any associations.

Both groups of children with severe and profound HL with HAs exhibit less favorable auditory perception on the soft speech level, but not at a conversational level, compared to children who are HH or deaf with CIs. Both groups, children with CIs and HAs, only exhibit more problems in planning and verbal memory than the norm groups of children who are TD. The results indicate that to obtain age-appropriate levels of receptive vocabulary and EF, the perception at the soft speech level is a necessary but not sufficient prerequisite.