Does the ultrasound affect humans? What precautions should I take using ultrasonication?
Ultrasonic frequencies itself are above the audible range of humans. The ultrasonic vibrations couple very well into solids and liquids where they can generate ultrasonic cavitation. For this reason you should not touch ultrasonically vibrating parts or reach into sonicated liquids. The airborne transmission of ultrasonic waves has no documented negative impact on the human body, as the transmission levels are very low. When sonication liquids the collapse of cavitation bubbles generates a screeching noise. The level of the noise depends on several factors, such as power, pressure and amplitude. In addition to that sub-harmonic (lower frequency) frequency noise can be generated. This audible noise and its effects are comparable to other machines, such as engines, pumps or blowers. For this reason we recommend the use of proper ear-plugs when being close to an operating system for longer time. Alternatively, we offer suitable sound protection boxes for our ultrasonic devices.
