Baby sign language does not interfere with speech therapy or delay verbal development. In fact, speech-language pathologists frequently incorporate signing into their therapeutic interventions for children with language delays, using carefully selected signs to give nonverbal children an alternative means of communication while they work toward verbal goals. A 2023 study published in the *Journal of Speech, Language, and Hearing Research* examined 56 deaf and hard of hearing children learning both ASL and spoken English and found that ASL vocabulary size positively correlated with spoken English vocabulary””meaning the more signs children knew, the more spoken words they also acquired. Consider a two-year-old who arrives at speech therapy unable to express basic needs.
The frustration of being unable to communicate often manifests as tantrums and withdrawal. When the therapist introduces signs for “more,” “help,” and “drink,” the child gains immediate tools for expression. Rather than replacing the motivation to speak, these signs frequently serve as a bridge, reducing frustration while verbal skills develop. This pattern appears consistently across clinical settings and research literature. This article examines the relationship between baby sign language and speech therapy in depth, covering what the research actually shows, how speech-language pathologists use signing in clinical practice, which children benefit most, and what parents should consider when navigating sometimes conflicting professional advice.
Table of Contents
- Does Baby Sign Language Delay Speech Development?
- How Speech-Language Pathologists Use Signing in Therapy
- Which Children Benefit Most from Sign-Supported Speech Therapy?
- Navigating Conflicting Professional Advice About Signing
- Research Limitations and What We Don’t Know
- The Parent Experience: Reduced Stress and Increased Connection
- The Future of Sign Language in Early Intervention
- Conclusion
Does Baby Sign Language Delay Speech Development?
The short answer, supported by decades of research, is no. None of the research studies on using sign language with babies have demonstrated that signing causes a delay in language development. This finding holds across typically developing children, children with language delays, and deaf or hard of hearing children learning both signed and spoken languages simultaneously. The concern about sign language replacing speech seems intuitive but misunderstands how language acquisition works.
Children don’t have a finite capacity for communication that gets “used up” by signing. Instead, early language exposure””whether signed or spoken””appears to support overall cognitive and linguistic development. As Corina Goodwin, a psycholinguist at the University of Connecticut, explained in 2021: “We find early exposure to language, whether signed or spoken, supports the development of typical cognitive skills.” One study found that children learned twice as many words when vocabulary was presented in speech and sign together compared to speech alone. This makes sense from a learning standpoint: seeing a sign while hearing a word provides two channels of input, reinforcing the concept and making it more memorable. The sign becomes a visual anchor for the spoken word rather than a competitor.
How Speech-Language Pathologists Use Signing in Therapy
When speech-language pathologists incorporate signs into therapy for children with identified language delays, their approach differs significantly from commercial baby sign programs. Rather than teaching a broad vocabulary of signs, SLPs carefully select specific signs based on each child’s individual communication needs and therapeutic goals. A child struggling with requesting might learn signs for desired objects, while a child working on social communication might focus on signs for greetings or turn-taking. The clinical use of signing for children with Specific Language Impairment follows this targeted approach. Research has found no evidence that signs impair oral language development in these children.
Instead, signs serve as scaffolding””temporary support structures that can be gradually removed as verbal skills strengthen. The child who initially signs “more” while attempting the word verbally may eventually drop the sign as speech becomes reliable. However, this clinical application comes with an important caveat. Parents sometimes assume that what works in therapy should be replicated at home without guidance, purchasing commercial programs and introducing dozens of signs simultaneously. This enthusiasm, while well-intentioned, may not align with the therapist’s carefully sequenced intervention plan. Communication between parents and SLPs about which signs to reinforce at home ensures consistency and maximizes therapeutic benefit.
Which Children Benefit Most from Sign-Supported Speech Therapy?
Research suggests that children who are linguistically behind their peers may show the greatest gains from sign-enhanced intervention. A study examining language outcomes found that low-ability children demonstrated a large increase in ability after signing intervention. This finding implies that gestures may benefit those with weaker language skills more than typically developing toddlers who are already on track with verbal development. For a typically developing 14-month-old, baby sign language offers benefits like earlier communication (children can begin signing as young as 9 months, approximately three months before typical speech onset) and potentially reduced frustration during the gap between comprehension and verbal expression.
The stakes are relatively low””the child will likely develop speech normally regardless. For a three-year-old with significant language delays, the calculus changes. Here, signs become a genuine communication lifeline, allowing the child to express needs, participate in social interactions, and experience the power of communication while verbal skills catch up. The research showing greater gains in lower-ability children makes sense in this context: children with more ground to cover have more opportunity to demonstrate improvement.
Navigating Conflicting Professional Advice About Signing
Not all professionals view baby sign language favorably, and parents sometimes encounter conflicting advice that creates confusion and stress. A 2025 study published in the *Journal of Deaf Studies and Deaf Education* interviewed parents and sign language teachers in the Netherlands and found that 25 percent of interviews included reports of negative attitudes or conflicting advice from professionals””including speech therapists””regarding sign language use. This professional disagreement has real consequences for families. Parents who receive discouragement from one clinician and encouragement from another must somehow reconcile contradictory expert opinions while making decisions about their child’s communication development.
The disagreement often stems from different theoretical frameworks, personal experience, or outdated training rather than from conflicting research evidence. When facing conflicting advice, parents can ask clinicians to explain the research basis for their recommendations. A professional advising against signing should be able to cite specific studies showing harm, which””based on current evidence””don’t exist. The National Association of the Deaf’s position statement emphasizes that early language exposure, whether signed or spoken, is critical for cognitive and language development in deaf and hard of hearing children. This principle extends to hearing children with language delays.
Research Limitations and What We Don’t Know
While the research on baby sign language is largely positive, it comes with significant methodological limitations that warrant honest acknowledgment. Canadian researchers Johnson, Durieux-Smith, and Bloom reviewed the sign language literature from 1980 to 2003 and found that of 1,208 published articles, only 17 met inclusion criteria for their systematic review. Benefits were reported in 13 of those 17 studies, but various methodological issues were noted throughout. The often-cited claim that children who signed as infants showed IQs 12 points higher than non-signing peers at age eight comes from researchers Acredolo and Goodwyn’s NIH-funded study.
However, this specific finding has not appeared in a peer-reviewed journal, limiting the scrutiny it has received and the confidence we can place in it. The finding may be accurate, but its status outside peer review means it hasn’t been subjected to the same rigorous evaluation as published research. Small sample sizes, lack of control groups, and the difficulty of isolating signing’s effects from other variables (like parental engagement, which tends to be higher in families who commit to teaching signs) complicate the picture. Parents should view baby sign language as a low-risk intervention with reasonable supporting evidence rather than a guaranteed path to specific outcomes.
The Parent Experience: Reduced Stress and Increased Connection
Beyond child outcomes, research has documented benefits for parents who use signs with their babies. Studies suggest parents who sign with their infants experience less stress and frustration and are more affectionate with their babies. This makes intuitive sense: when a parent can understand what their 10-month-old wants, the constant guessing game that characterizes early parenting becomes less exhausting.
A parent who notices their baby signing “milk” has information that would otherwise require cycling through possibilities””diaper change, nap time, toy, hunger””until landing on the right answer. This efficiency reduces the tension of miscommunication and may explain the finding that children who learned to sign during infancy have fewer tantrums, as documented by Acredolo and Goodwyn in 2002. The child’s frustration at not being understood and the parent’s frustration at not understanding both diminish when a shared communication system exists.
The Future of Sign Language in Early Intervention
Recent research continues to build the evidence base for sign language’s role in early development. Indiana University’s Early Literacy blog published research in February 2025 on how baby sign language boosts early literacy skills, connecting sign exposure to broader educational outcomes. This expanding research focus””from immediate communication benefits to longer-term academic implications””reflects growing recognition that early signing may have effects beyond the toddler years.
The trajectory of professional attitudes also appears to be shifting. While the 2025 Dutch study revealed that some professionals still discourage signing, the research community’s overall direction supports sign language as a complement to speech therapy rather than a contradiction of it. As training programs incorporate more current evidence, the conflicting advice that currently frustrates parents may become less common.
Conclusion
Baby sign language and speech therapy work together rather than against each other. The research consistently shows that signing does not delay speech, that speech-language pathologists strategically use signs as therapeutic tools, and that children with language delays may benefit more from signing than typically developing peers.
The key is understanding signing as a bridge to verbal communication rather than a replacement for it. Parents considering baby sign language alongside speech therapy should communicate openly with their child’s SLP about coordinating approaches, ask for research-based explanations when encountering professional skepticism, and maintain realistic expectations about outcomes. The evidence supports signing as a low-risk, potentially beneficial intervention””not a magic solution, but a legitimate tool in supporting children’s communication development.