Ultrasonic Noise Sources in a Work Environment

Abstract

The use of ultrasonic energy has created versatile possibilities of their applications in many areas of life, especially in hydro location and underwater telecommunications, industry and medicine. The consequence of a widespread use of high intensity ultrasonics in technology is the increased number of people who are exposed to such ultrasonic noise. Therefore it is important to determine the types of machines and other devices that are responsible for the emission of ultrasonic noise (10-40 kHz of central frequencies of one-third octave bands) as harmful and annoying hazard in the work environment. This paper presents ultrasonic noise sources frequently used in industry and preventive measures reducing the exposure to ultrasonic noise. Two types of ultrasonic noise sources have been distinguished: machines and other devices used to carry out or improve production processes, the so-called technological sources and sources in which ultrasonic noise exists as a non-intentional result of operation of many machines and systems, the so-called non-technological sources of ultrasonic noise. The emission of SPL has been determined for each groups of devices based on own measurement results.

Reducing the harmful effects of noise on the human environment. Sound insulation of industrial skeleton enclosures in the 10–40 kHz frequency range

“…The fundamental parameter characterising quantitatively the intensity of sonic phenomena (including noise) in the frequency range 20-20,000 Hz is the Aweighted sound pressure level. Any noise characterised with values of that parameter exceeding 80 dB [1][2][3][4][5][6][7] can be the cause of permanent damage of hearing in a human being. In Poland, the A-weighted sound pressure level of 85 dB is adopted as the so-called maximum admissible intensity (MAI) applicable in the context of the hearing protection [2,3].…”

Methods of Testing of Sound Insulation Properties of Barriers Intended for High Frequency Noise and Ultrasonic Noise Protection

“…Ultrasonic cleaners are the most common devices. They are sources of emission of ultrasounds whose sound pressure levels at operator workplaces reach the values of 110÷135 dB [3,4]. The ultrasonic cleaners are followed by ultrasonic drilling machines and ultrasonic welding devices.…”

“…Besides technological ultrasonic devices, there is also a large group of industrial machines and devices which also emit ultrasounds as an unintended, accompanying additional factor. The sources of the ultrasounds are phenomena of the aerodynamic nature or the mechanical nature [4,6].…”

Measurement of Earmuffs Attenuation at High Audible Frequencies

“…Noise in the audible frequency range above 8 kHz is generated for instance in places where high-speed cutting machines are operated (non-ferrous metalworking), while using hand tools such as angle grinders or testing jet aircraft engines, and also where compressed air valves are used (Smagowska, 2013). Such noise can cause dizziness, headaches, loss of balance, nausea, and tinnitus.…”