IEEE 269A:2007 pdf free download

IEEE 269A:2007 pdf free download.IEEE Standard for Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets,Handsets, and Headsets.
Additionally, for binaural headsets, the following applies:
d) For headset that do not have left and right ear wearing indication, it can be tested on a HATS that is eQuiPped with one functional ear simulator. The primary receiver (where the micmphonc system is located) should be positioned on the functional car simulator for all tests. The secondary receiver shall be moved into position for evaluating frequency response, RLR_and distortionmeasurements.
e) For headsets that are designed to be worn in only one manner or fashion, then a HATS with two functional ear simulators shall be used. The two receivers shall be tested separately. The secondary receiver need only be tested for frequency responç, RLR and distortion.
The test position shall define how the receiving part of the headset is to be placed against or inside the car simulator. After providing receiver placement instructions, the test position shall then describe the subsequent positioning and orientation of the microphone.
The exact positioning of the microphone shall be specified using geometric coordinates relative to centre of lips using three axes (See ITU-T Rev. P.64):
f The Xaxj incides with jhgjouth reference axis and has positive direction jt!tQjhe
motiih.
g) The Y,, axis is horizontal. peendicular to the X,. axis with positive direction towards the right side of the head.
h) The Z, axis is perpendicular to the X axis and axis with positive direction upwards,
The closer the microphone is to the mouth, the more sensitive the results will be to any inaccuracy of the geometrical positioning. Pressure gradient microphones (vardioid. noise canceling. etc.) are especially sensitive to both position and orientation. The recommended orientation of the microphone towards the mouth shall he stated. For headsets that are fixed at the ear, and have a short microphone boom configuration, then the receiver coupling provides the main positioning element, with the boom pointed at
MRP.
When positioning a headset on a HATS, it is generally possible to approximate real usc in an obvious way. In any case where the headset does not fit on the HATS and its ear simulator quite in the way intended for real persons, adiustments may be made so the receiver and microphone are as close as possible to positions corresponding to real use. Particular caution should be exercised when posiIionin receivers (such as car buds) near or in the ear canal, as they are subject to more variation than other receiver ts. The body of the receiver, the headband or any other non-acoustical coniponent may be positioned as necessary.
Jigs may be used lo improve repeatability of positioning provided that they do not cause any acoustic impaint to the measurement.
The test operator should become acquainted ith the specific headset by running some preliminary learning tests.