Can sounds you can’t hear damage your hearing?  At birth, the human inner ear is sensitive to sound frequencies up to 20 kHz, and this upper limit gradually falls over the life course.  Ultrasound – sound above this frequency might therefore be thought to be safe (although not for your dog).

However, whilst we don’t know all of the specific effects of ultrasound on human health and well-being – a question this paper is seeking to stimulate - there is little doubt that high intensity noise is damaging, and that higher frequency noise is more damaging than low. A potential consequence of damaging the inner ear by loud sounds is reorganization of the central auditory pathways – a form of neural plasticity that has been associated with tinnitus.

Ultrasound (or near ultrasound) frequencies has been used as a ‘deterrent’ to teenagers hanging around corner stores – on the basis that adults can no longer hear these sound frequencies. But why should shop owners be allowed to direct potentially damaging noise at teenagers to encourage them to move on? Babies (who also tend to hang around shops – and with little choice in the matter) might be affected more so.

Our understanding of the effects of loud noise on our communication abilities is changing rapidly – and is coming to the view that it is more damaging than we previously thought. This papers call for a review of current recommendations is timely.