Ivanov N., Copley D., Kurtsev G.

Sound field of a sound-proofed and vibration isolated cab is complex. Cab spectrum is characterized by domination of low-frequency components. Most significant noise levels are found in extremely low frequency range. These contributions are caused by cab air volume oscillations. Structure-borne noise contribution is also considered. Other frequency components are formed by different noise sources contributions yielding non-uniform sound fields at the cab outer frames. Magnitude of particular noise source contribution depends on sound isolation of cab panels, on acoustical tightness of cab, on cab sound absorption, and on diffraction at cab elements. Results of experimental and theoretical studies of cab noise are presented. Analytical equations for separation of noise sources contributions are given.