Hearing thresholds, tinnitus, and headphone listening habits in nine-year-old children.

The study measured children at one time, so it cannot show that headphone use caused poorer hearing thresholds. Testing was done in schools rather than a standard audio booth, although the room was quiet and attenuating headphones were used. Temporary threshold shift after recent noise exposure could not be ruled out before testing. The hearing-threshold differences linked to headphone use and tinnitus were statistically significant but small, and the paper notes clinical relevance should be discussed. The abnormal hearing threshold definition was 20 dB HL or more at one or more frequencies, a conservative cut-off that may include mild or temporary threshold shifts. Middle-ear abnormalities were common and can cause temporary threshold changes for months, so some threshold differences may reflect middle-ear status rather than inner-ear loss. Tinnitus was classified after an audiologist-led discussion with the child, not solely from a simple self-report answer. Headphone exposure was recorded only as never, seldom, 1-3 times per week, or daily, so the dose of listening was not measured. The number of children analysed differed across outcomes, so prevalence figures are not all based on the same denominator. Children with a cold, ventilation tubes, or a perforated eardrum were excluded, so the sample may not represent all nine-year-olds.

Do not conclude that headphones caused hearing loss in these children. This was a cross-sectional study, and the significant differences in hearing thresholds were small; recent noise exposure and middle-ear problems could also affect the results.