Introduction Although the possible negative health effects of exposure to high energetic ultrasonic noise were discussed since the adoption of the technology in the 1940s, no major research was conducted on this topic since the late 20th century and it only regained focus approximately 10 years ago. Nevertheless, guideline values and limits have been established for the exposure to ultrasonic noise in several countries. The Ears II project was brought to life under the umbrella of the EU’s EMPIR, to investigate the human perception of non-audible sound and its possible effects on human health. In this context the Institute for Occupational Safety and Health and the National Metrology Institute of Germany developed a measurement technique for assessing industrial ultrasonic noise.

Methods Existing measurement techniques for audible sound were evaluated for their applicability to measuring ultrasound. Through evaluation of existing data a reference workplace was developed for laboratory measurements. These comprised simulated practical measurements and high spatial resolution scans of the sound field of an ultrasonic welding machine. Finally, a method was developed and tested in field measurements.

Results The existing standards for assessment of the exposure to noise negate the applicability to ultrasonic noise. The same is true for the standards covering technical requirements for sound level metres. A novel technique was successfully developed and field measurements were carried out.

Conclusion The existing standards are mostly insufficient for the assessment of the exposure to ultrasonic noise. Either applicability to ultrasound is ruled out a priori or the methods or technical specifications are insufficient for the measurement of ultrasound, because the frequency range of interest is not covered, for example.

Based on an existing guideline a novel method was developed, which will, if necessary, be adapted to practical needs after examination of its practical applicability by evaluation of the field tests.