Measurement procedure
•Each device was
measured 5 times, dismounting and remounting the headphones each time, as recommended by standard EN 50332, in order to reduce the mounting error. The
results were then
averaged.
•For ensuring a
better correlation between the results and in order to minimize the measurement time, we used the same headphone position with both test signals (IEC and
MUSIC). The headphone
was inserted, then the two signals were measured and then the headphones were removed and
reinserted.
•The volume control
of the player was left untouched since the last usage from the owner of the device. These results
are thence not significant
for discriminating "dangerous" devices from "safe" devices.