Moshammer et al1 have recommended routine implementation of a temporary threshold shift (TTS) screening test to identify workers particularly at risk of developing noise-induced hearing loss (NIHL) from occupational exposure to hazardous noise. Their work addresses an important occupational health problem. NIHL ranks among the most common work-related injuries in many countries, with an estimated global annual incidence of 1.6 million cases, and accounts for approximately 16% of disabling adult hearing losses worldwide.2 ,3 Individuals vary in their susceptibility to the damaging effects of noise and no suitable method currently exists to predict the susceptibility of a particular worker.

In their study, Moshammer et al measured TTS in newly hired employees following exposure to a 20 min, high-intensity, low-frequency experimental noise. They then followed the workers over time to see who ultimately developed a permanent threshold shift (PTS). The authors report that a TTS of 14 dB or more measured 2.5 min after the experimental exposure identifies workers at greater risk for PTS. They recommend routinely using this procedure to screen for susceptibility to noise in workplace hearing loss prevention programmes.

However, this recommendation is premature in view of the study results. The TTS measure had a sensitivity of 82%, meaning that 18% of those who developed PTS were not identified by the TTS screening—a …