Hearing loss in relation to educational attainment and cognitive abilities: a population study.

Severe hearing loss among children has often been found to be associated with educational disadvantage and lower-than-average performance on cognitive tests, but less is known about the much more widespread milder levels of hearing loss. In a cohort of 22 162 young Danish men appearing before the draft board, about 75% had normal hearing at 20 dB, and about 20% had mild hearing loss not worse than 25 dB in both ears for all tones less than 3000 Hz, and not worse than an average of 45 dB in both ears for all tones above 2000 Hz. The remaining 5% had more severe hearing loss. The proportions who had continued school education after age 16 years among the three groups were 51%, 42% and 34% respectively and their mean IQs were 101, 98 and 94. The evidence suggests that even mild hearing loss is associated with distinct educational and cognitive disadvantage which itself may result from difficulties in following classroom teaching.