Effects of low-intensity exercise and noise exposure on temporary threshold shift

It is not known if an individual who is susceptible to temporary threshold shift (TTS) may also suffer permanent hearing loss. Risk for hearing loss is caused by the physical properties (frequency, intensity, and duration) of noise and other possible factors including physical exercise. Seventeen subjects cycled at 40% of maximum oxygen consumption (VO2 max) with and without noise administered via personal headphones. Exercising at 40% of VO2 max is considered to be low intensity. Hearing tests before and after these two exercise conditions and a noise-only condition indicated that TTS only occurred when noise was present, that is, exercise alone did not result in TTS. Therefore TTS and subsequent hearing loss (which only persisted for 24-48 h) was found to be driven by noise exposure, not low-intensity exercise.