Operating Instructions MA 53Geba_MA53_e_13a.doc 3 851 430/3 11/116.14 Talkback microphone and Monitor volume control ............................. 336.15 Speech audiometry ............................................................................ 336.16 Speech calibration ............................................................................. 336.17 User menu ........................................................................................ 347 Advanced features.................................................................................. 367.1 Complex mixing .................................................................................. 367.2 Advanced Noise Selection .................................................................... 377.3 Talk-back microphone ......................................................................... 377.3.1 Connection of the talk-back microphone ....................................... 377.3.2 Adjustment of the talk-back microphone ....................................... 377.4 Assistant phone ............................................................................... 387.4.1 Connection of the assistant phone ................................................ 387.4.2 Adjustment of the assistant phone ............................................... 388 Recommended literature......................................................................... 399 Computer interface ................................................................................ 4010 Care and maintenance of the instrument .............................................. 4111 Trouble shooting .................................................................................. 4212 Technical Data ...................................................................................... 4313 Warranty, Maintenance and After-Sales Service ..................................... 5114 Safety Regulations ................................................................................ 5214.2 Measuring security: ........................................................................... 5214.3 Device control: .................................................................................. 5214.4 Operation:......................................................................................... 5214.5 Patient Safety: ................................................................................... 52