Demographic and phenotypic profile of study sample with pure-tone audiogram data.

The study sample was separated into monozygotic twins (MZ), dizygotic twins (DZ) and singletons. Each group was further described by its sample size (n), age-range, mean age, pure-tone average (PTA), principal component 1 (PC1), principal component 2 (PC2) as well as their difference (PC1–PC2) and better ear hearing level threshold (BEHL) values. Measurements for the mean age, pure-tone average and principle components are given as mean with standard deviation (SD).