9Bilingual-Bimodal: Sign and Spoken Together

FThe both-and model

A bilingual-bimodal approach raises a deaf child with two languages in two modalities: a natural sign language alongside a spoken language accessed through a cochlear implant. The term bimodal captures that the two languages travel through different channels, the eyes and the ears, rather than competing for the same one. Instead of treating implant and sign as rivals, this model treats them as complementary tools serving a single goal of a fully languaged child.

The approach grew partly from the realization, covered in the preceding modules, that the worst outcome is no fluent language at all. If a sign language can be established early and reliably, it provides a guaranteed first-language foundation while spoken language develops through the implant, and many families and clinicians have adopted exactly this both-and stance.[2014][2012]

TThe encouraging evidence

Several lines of evidence suggest that early sign language need not come at the expense of spoken language. Studies of deaf children of deaf parents, who acquire sign natively from birth, have reported cochlear-implant outcomes at least comparable to deaf children of hearing parents, challenging the assumption that a signing home undermines spoken development. Detailed studies of native-signing children with implants have likewise found spoken-language scores reaching age-appropriate, monolingual-like levels.

More recent work measuring sign and spoken vocabulary in the same bilingual children has reported a positive association, with larger sign vocabularies accompanying, not subtracting from, spoken vocabularies. The mechanism proposed is that a strong first language, in whatever modality, provides linguistic scaffolding that transfers to the second, consistent with what is seen in bilingual development generally.[2012][2014][2023]

CWhere the evidence is contested

The picture is genuinely contested. A large multisite cohort study reported that children with no or only brief early sign exposure achieved better auditory, speech and reading outcomes than children with sustained sign exposure, a finding read by some as evidence that emphasizing sign can slow spoken progress. This study has been influential and is frequently cited by those favoring an auditory-oral emphasis.

Critics counter that observational studies of this kind struggle to separate cause from confound: families who turn to sign may do so because the implant is already underperforming, and the quality and fluency of sign input is rarely measured, so apparent harm from sign may actually be the footprint of language deprivation or selection effects. The honest summary is that the studies disagree, partly because they measure different children, different kinds of sign exposure, and different outcomes.[2017][2017]

CHolding the both-and stance honestly

Given conflicting data, a defensible clinical stance neither promises that sign turbocharges speech nor warns that it sabotages it. What the strongest evidence supports is that fluent, high-quality early language in any modality is protective, and that a well-supported bilingual-bimodal path can yield strong outcomes in both languages, particularly when sign input is genuinely fluent rather than fragmentary.

Honest counseling therefore presents the both-and model as a reasonable, evidence-informed option rather than a guaranteed optimum, names the open questions about timing and intensity, and respects family values. The unifying commitment across the disagreement is to prevent a child from being left without any fluent language, which is the one outcome the data agree is harmful.[2023][2017]