The characterization of noise emitted by a machining centre
located in a workshop can be difficult since the all the equipment in
the vicinity disturb noise measurements. Moreover, even if all the
equipment is switched off, the enclosures and the walls of the
buildings reflect noise, which disturb measurements [4]. For this
reason, it is necessary to make such measurements in an anechoic
chamber. An anechoic chamber with a hard floor was specially
designed and built around a PCI METEOR 5 machining centre. The
machining centre is a 4-axis horizontal machine typically used to
produce aluminium parts in automotive machining plants. The
dimensions of the chamber are presented in Fig. 2. The inside walls
are built from ROCKFON1 stone wool acoustics ceiling (ISO11654
absorption coefficient aw in the range 500–5000 Hz) so as to avoid
noise reflection and transmission from outside. In contrasts the
outside walls consist of metallic cladding so as to facilitate external
noise reflection