The digit triplet test for school-age hearing screening: comparing languages, school grades and scoring methods in a large sample.

Objective: To investigate the reliability of a bilingual school-age hearing screening in four school grades based on the Digit Triplet Test (DTT) in two languages and to investigate three calculation methods for referral values in their ability to detect hearing losses and avoid false-positive results.

Design and study sample: 3255 children, aged between 10 and 17 years old, were tested during a systematic hearing screening program in a bilingual, French-German area in Belgium. French speaking children were tested with a French DTT, German children were tested with a German DTT. The SRT-values, their stability and measurement error were investigated per grade and language. The number of false-positive results was studied for three referral methods, using additional audiometric data of 71 children.

Results: Our data showed that reliable results with high stability and a small measurement error can be obtained in only around two minutes per ear. Differences between languages are minimal and grade-specific referral values were necessary. A referral method considering the lowest SNRs in the adaptive staircase reduces the number of false-positive results substantially.

Conclusion: The DTT versions of different languages can be used reliably in a bilingual school-age hearing screening program when grade-specific, alternative referral methods are implemented.