Note: Switch is the default setting.To change the sound mode:1. Use 34to locate the sound mode menu on base display.2. Use 56 to select one of the 3 modes from the menu, and choose betweenfixed/switched from the menu.3. Press OK to confirm the setting.2.5.5 Protection level selectionYour headset offers a choice of 4 protection levels (plus its additional basic protection level).These levels protect you against sudden, overly-loud sound spikes that may come from thephone network (such as shrill telefax signals or network interference), and provide a limit tothe maximum noise exposure from the headset during your workday.The number of hours (on average) you spend on the telephone per day determines the set-ting you should select. All 4 protection levels meet and exceed de facto global protectionlevels, and are compliant with NIOSH standards, and EU health and safety codes of 85 dB(A).The TT4 protection level is compliant with pertinent Australian recommendation.Important: In some jurisdictions, applicable regulations or laws may mandate the required settingyou use. The Default level provides a protection level of 118 dB(A). Your headset protects youagainst overly-loud sound spikes. If you use the telephone’s handset for calling, you will not havethis protection.Protection level Criteria for selectingLevel 0 Basic protection against overly-loud sound spikes[118 db(A)]. Auto volume disabledLevel 1* Less than 4 hours on telephone/dayLevel 2* 4-8 hours on telephone/dayLevel 3* More than 8 hours on telephone/dayLevel 4 (TT4) Recommended Australian protection level (Telstra)* Compliant with Directive 2003/10/EC of the European Parliament and Council of 6 February 2003.To change the protection level:1. Use 34to locate the protection level menu on base display.2. Use 56 to select one of the 5 modes from the menu.3. Press OK to confirm the new mode.8