“Please repeat that number”: Auditory health literacy and recall of SMS hotline details in Sepedi-language health bulletins on Botlokwa FM, Limpopo, South Africa

This article examines how listeners to Botlokwa FM in rural Limpopo, South Africa, hear, process, and recall SMS health hotline numbers embedded in Sepedi-language radio bulletins.Methods: Working with an integrated framework that combines auditory health literacy, information processing theory, and the "mode as filter" model, the study investigates how on-air design choices shape access to mobile health services.A mixed methods design was used: 120 adult Sepedi speakers from three villages listened to experimentally varied recordings of a real health bulletin, completed immediate and delayed recall tasks, and participated in short interviews about listening practices.Results: Bulletins with two clear repetitions and number placement at the end produced significantly higher full-number recall than single-mention or mid-bulletin conditions, while age, schooling, and smartphone use also influenced performance.Qualitative findings show how listeners depend on repetition, shared listening, and written notes.Conclusion: The study advances communication scholarship by conceptualising methodological voice bias in auditory health environments and offers concrete design principles for radio-linked mHealth services in low-resource settings.