What the Research Says
We turned to the academic literature available on this question but struggled to find a clear ‘one-case fits all’ example. While some studies showed that children with tongue ties have “worse” speech outcomes, others found that children with tongue ties can learn to compensate for their tongue-tie, with limited effect on speech production. However, it is difficult to make any definitive conclusion from these studies due to several reasons.
First, there is a limited number of studies, most of which examine a small sub-set of children, and some of which are not methodologically sound.
Second, there is no consistent way of measuring the “impact” of the tongue-tie on speech. Some studies measure over-all “intelligibility” (i.e., how well do listeners understand what the child is saying), while other studies measure specific articulation errors consisting of substitutions, omissions, or distortions of sounds. This is problematic as a child’s speech may consist of sound distortions, while still being intelligible. Yet we cannot say that having sound distortions is an acceptable outcome.
Third, the literature does not appear to take into account the severity of the tongue-tie. It has not appropriately examined whether more severe tongue ties have more significant impacts on speech, for example.
Our Professional Opinion
Consequently, we feel that the literature currently available on the impacts of tongue-tie on speech outcomes does not provide sufficient convincing evidence for us to make a binary conclusion on this matter. We cannot definitely say that there is “no effect”, but we also cannot definitely say that there ALWAYS is one. We feel that we have to view the circumstances case by case, and each case must examine other factors that could be impacting the speech clarity of a child with a tongue-tie (e.g., hearing loss, language delay). We believe that ultimately our role is to provide the information available, along with its limitations, discuss the individual factors involved and what we observe, and allow parents to make an educated decision on this matter.