Noise exposure from communication headsets (during phone calls as well as while awaiting them) was evaluated using a microphone in the real ear (MIRE) technique, as specified in ISO 11904-1:2002.[6] According to this standard, a miniature microphone probe, the SVANTEK type SV25S (connected to the one of two available inputs of the dual-channel acoustic dosimeter type SV102) was placed at the entrance of the open ear canal of call center operators, and the aforesaid noise parameters together with SPLs in 1/3-octave bands (from 20 to 10,000 Hz) were determined. Simultaneously, the second channel of dosimeter (equipped with a SVANTEK standard 1/2-in. microphone type SV25D) was used for assessment of noise exposure outside the other ear.