Sennheiser HDA 300 Instruction Manual - Page 7

Connecting HDA 300 to an audiometer and calibrating the audiometer Connecting the HDA 300 to an audiometer and calibrating the audiometer In order to obtain accurate measurements, the audiometer has to be re-calibrated on a regular basis and each time the audiometric headphones are exchanged. This is necessary even if you change the climatic conditions. Connecting the HDA 300 ̈ Connect the red plug of the headphones to the right channel and the blue plug to the left channel of the audiometer. ̈ Have an authorized specialist calibrate the audiometer together with the HDA 300. Preparing the HDA 300 for calibration You can find the appropriate reference threshold sound pressure levels on the fold-out page of the cover or at www.sennheiser.com on the product page for the HDA 300. 1 Adjust the HDA 300 as shown in the diagram. 2 Place the ear cap on the middle of the coupler so the distance to the top, bottom, left and right is identical. a 143 mm b b 145 mm a Storing the HDA 300 ̈ Do not store the headphones stretched out for long periods as this can widen the headband and reduce the contact pressure of the headphones. ̈ Make sure that the headphone cable does not cross any passageway to avoid anyone tripping over the cable. ̈ Handle the headphones and the cable with care. Do not twist, damage or kink the cable. HDA 300 | 5