Do you like my voice? Stakeholder perspectives about the acceptability of synthetic child voices in three South African languages.

BACKGROUND

There is a global need for synthetic speech development in multiple languages and dialects, as many children who cannot communicate using their natural voice struggle to find synthetic voices on high-technology devices that match their age, social and linguistic background.

AIMS

To document multiple stakeholders' perspectives surrounding the quality, acceptability and utility of newly created synthetic speech in three under-resourced South African languages, namely South African English, Afrikaans and isiXhosa.

METHODS & PROCEDURES: A mixed methods research design was selected. After the creation of naturalistic synthetic child speech which matched the vocal identity of three children with expressive communication difficulties, those three children answered questions about the quality, acceptability and utility of the synthetic voices using a pictographic three-point scale. A total of 11 adults who are known to the children participated in subjective quality assessments in the form of mean opinion scores, intelligibility tests and focus group discussions.

OUTCOMES & RESULTS: Despite the synthetic adult voices appearing more natural, stakeholders were accepting of all the synthetic voices. Although personalization of the voices is important, intelligibility is prioritized and standard dialects are often preferred. When communication partners have adequate training and are willing to model and support children in all environments, children with expressive communication difficulties thrive, but when augmentative and alternative communication (AAC) use is inconsistent, there is reduced vocabulary development and poor system transitioning, and AAC abandonment is greater.

CONCLUSIONS & IMPLICATIONS: This research suggests that stakeholders from low- and middle-income countries are interested in the development of synthetic voices in their home languages. Our research highlights that children would prefer to incorporate these voices on their high-tech devices, and adults would prefer them for their children, learners and/or clients' devices, rather than using British or US English voices.

WHAT THIS PAPER ADDS

What is already known on this subject Caregivers, service providers, peers and other communication partners play a substantial role in a child AAC user's early communicative success, and their acceptance of AAC ultimately influences the effectiveness of the intervention. When communication partners advocate and support the inclusion of specific speech-generating devices, AAC applications, and suitable synthetic voices, children are more willing to consistently utilize the technology. What this paper adds to the existing knowledge As literature focusing on stakeholder perspectives from low- and middle-income countries is less common than research from high-income countries, and often lacks input from multi-perspective stakeholders, our study offers a unique perspective from South African children with expressive communication difficulties, caregivers of those children, their speech-language pathologists and teachers, about the quality, acceptability and utility of synthetic speech in under-resourced languages. What are the potential or clinical implications of this work? Our research highlights that stakeholders would prefer South African languages and dialects on South African speech-generating devices, rather than relying on devices that only incorporate British or US English voices. The development of synthetic speech in under-resourced languages has the potential to support marginalized AAC communities. Children with expressive communication difficulties would finally be able to participate in class and do so with a voice that matches their age, gender and social and linguistic background. This paper highlights the importance of providing a variety of synthetic voice options and emphasizes the significance of introducing novel voices for high-tech AAC to children in a manner that respects and aligns with their linguistic and cultural backgrounds.