device and system are provided for monitoring acoustic emissions from machinery to indicate levels of detected sound waves. Each incorporates an acoustic sensing device which incorporates a housing assembly constructed for removable attachment between a surface mounting region of the machinery and a measuring instrument to define a coupled state. An acoustic emissions sensor is disposed in the housing assembly's interior to detect sound waves propagating through the surface mounting region and to produce detection signals for processing by the measuring instrument. A methodology for monitoring acoustic emissions is also provided.