The Digit Triplet Test (DTT) correlates strongly with pure tone audiometric measures, so may be regarded as a measure of hearing impairment. Continuous DTT data may be used in correlation-based analyses.

One may also wish to describe the proportion of participants who have levels of hearing impairment significantly below the normal range (for example, the proportion of hearing impaired males versus females, or diabetics versus non-diabetics with impaired hearing). In previous research with the DTT and in the telephone screening versions of the DTT, its performance has been categorised with reference to a group of young adults with normal hearing (Hall, 2006; Smits, Kapteyn, & Houtgast, 2004; Vlaming et al., 2011).

This document describes how the DTT performance categories were derived for the version of the DTT used by UK Biobank, and provides DTT performance categories which may be used to interpret DTT data.

This resource can be downloaded or viewed using the link: DTT_normative_values_Dawes_Nov13.pdf

If you have wget available (typically on linux systems), then you can also obtain a copy using the command

 wget  -nd  biobank.ndph.ox.ac.uk/ukb/ukb/docs/DTT_normative_values_Dawes_Nov13.pdf