Abstract
CONGENITAL AMUSIA
,
OR
‘
TONE DEAFNESS
,’
IS A LIFELONG
impairment in musical ability, reported to be present in
approximately 4% of the general population. We exam-
ined the meaningfulness of 4% as an estimate of the
prevalence of amusia given current test-based methods;
here we focused on the Distorted Tunes Test (DTT) and
the Montreal Battery of Evaluation of Amusia (MBEA).
We demonstrate that estimates of prevalence critically
depend on the specific cutoff applied to the test and the
degree of skew in the distribution of scores. Broader con-
sideration of this issue reveals that the use of arbitrary
cutoffs is not unique to diagnosis of congenital amusia.
We conclude that although the MBEA has shown to be
a valuable diagnostic tool, caution is warranted against
attributing meaning to the reported 4% rate of congen-
ital amusia that is so widely cited in the literature.