The subject contains the description of characteristics of acoustic field in
connection with criteria for hearing hazards. Further, it deals with noise
spreading in constructions and noise reduction, the way of spreading noise
from the source, and the methodology of noise measurement. Electroacoustic
converters are a basis of the next part, which discusses measurements in
acoustics and electroacoustics, including sound recording and reproduction.
Ultrasound and ultrasound defectoscopy methods are considered in terms of
ultrasound defectoscopy and ultrasound check technology.