IEEE 269A-2007 pdf download IEEE Standard for Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets, Handsets, and Headsets
Change the last paragraph as shown:
The Type 3.3 ear simulators shall comply with the specifications given in ITU-T Recommendation P.57-2002. The Type 3.3 shall have a hardness of 35 +6 degrees Shore-00, as measured according to ASTM2240.(ITU-T Recommendation P.57-2002 originally specified a hardness of 55 -10 degrees Shore-O0 forType 3.3.)
5.1.2 Measurements made on the Type 3.3 ear simulator compared to real ears
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Iype 3.3 and Type 3.4 ear simulators beth simulates the acoustical and mechanical characteristics of realears the median human ear. They-are It is likely to give results comparable to the typical listeningexperience of real persons for the widest possible variety of headsets, handsets and similar devicesHowever, the correlation between easurements on ear simulators and on real ears is better for someheadset types devices than others. For headsets that are in elese proximity to, 0r in the ear eanal, theeerrelatien is net as geod as for most ether types.
he correlation for headsets that are in close proximity to, or in the ear canal, is not as good as for mostother types. For insert headsets, both-the Type 3.3 and Type 3.4 ear simulators are likely to ear simulatoimay provide a greater seal than on many human subjects, resulting in an overestimation of output at lowrequencies. Nonetheless. beth ear-shmaters-are the Type 3 3 ear simulator is recommended for thiapplication.
5.1.3 Translation from DRP to ERP
Change the first sentence ofthe first paragraph as shown:
Iype 3.3 and Type 34-ear simulators both measure ear simulator measures at the eardrum reference point(DRP).
5.3 Test fixtures
5.3.2 Handset positioning
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for many handsets. the car-cap reference plane is arallel to the reference plane of the positioning deviceFor some handsets, the above positioning may not apply, and the position that best represents intended useshall be utilized. The reeeiver shall eontaet the pinna with a foree of 6N (newtons). This is the default foreeforall measurements.
in general. it is desirable that receive frequeney response should not change too much as applieation forcechanges. For this reason, the device should also be tested at 2N and 10N, whieh represent minimum andmaximum forees likely to be used by real persons on a long-term basis. These results are for information.but do not have to be ineluded in the test report.
(One could experience a foree of approximately 10N by plaeing a weight of 1 kg on top of a lightweightreceiver placed on his or her pinna, with the ear cap reference plane horizontal.) A manufacturer mayspeeify a reeommended test position (RTP) on either the Type 3.3 or Type 3.4 ear simulator, The RTP mayspeeify position with respeet to ERP,a speeifie foree. or ther aspeets of the test position intended tosimulate aetual use. The foree applied shall not exeeed the range of 2-10 N.
If the phone is tested at the RTP, the definition of the RP, ineluding evidenee of its authorization by thedeviee manufaeturer. shall be ineluded in the test report. lf the RTP is used. the deviee should also be testedat 2N 6 N, and 10N on the same ear simulator These results are for information, but do not have to beneluded in the test report. For maximum acoustie output measurements, the device shall be tested at either6N or the RTPand also at 13 N. The final result shall be an “upper envelopecurve consisting of themaximum output of eaeh measurement at each frequeney, See Figure 1 and pigure 2.
IEEE 269A-2007 pdf download
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