Development and evaluation of the Ghanaian digit triplet test for adult hearing screening

This study aimed to develop and evaluate a Ghanaian Digit Triplet Test for adult hearing screening.

The study was conducted in two phases. Phase 1 optimised digit recognition across speech materials in a controlled environment, while Phase 2 collected normative data and assessed list equivalence using an adaptive and fixed-level method.

Eighty adults aged 18 to 50 years with normal hearing thresholds (≤ 15 dB HL) participated: 16 in Phase 1 and 64 in Phase 2.

The mean SRTs were -11.3 dB for Asante-Twi and -11.4 dB for Ghanaian English, closely matching other digit triplet tests. Psychometric slopes were 17.9%/dB for Asante-Twi and 19.4%/dB for Ghanaian English. No significant differences were found in SRTs across list numbers or orders for the Asante-Twi version, indicating list equivalence and no learning effect. However, a significant learning effect in the Ghanaian English version necessitated different normative values based on participants' test exposure.

The GDTT demonstrates consistency with other digit triplet tests while addressing specific linguistic and cultural factors. The test can improve access to hearing screening in resource-limited settings in Ghana. Further research should explore the test's applicability to a broader demographic, including children.