IEEE 269a:2007 pdf free download – IEEE Standard for Methods for Measuring Transmission Performance of Analog and Digital Telephone Sets,Handsets, and Headsets
5.3.2.1 Standard test position (STP)
For STP, the handset receiver must be nominally placed in the HATS position as specified by Annex D orAnnex E of ITU-T Recommendation P.64-1999.To do this, the ear-cap reference point (ECRP) must lie onthe axis of motion of the positioning device. This axis is defined by a line that passes through the ERP ofthe left and right ears. It is parallel to the Ym axis (see ITU-T P.64-1999,Annex E).The ECRP may beinside of or outside of ERP depending on the applied force and the shape of the receiver.
Unless otherwise specified by the manufacturer、the ECRP is the intersection of the external ear-capreference plane (ECRP Plane) with a normal axis (xe axis as defined by ITU-T P.64-1999,Annex E)through the effective acoustic center of the sound outlet ports. Generally, the acoustic center of the soundoutlet ports is at the center of their distribution. For many handsets,the ECRP plane is parallel to thereference plane of the positioning device.
ln general,it is desirable to know how the receive frequency response and loudness rating change asapplication force changes. For this reason, the device shall be tested at a high leak position and a low leakposition, which represent loosely coupled and firmly coupled conditions.
For the Type 3.3 ear simulator,the high leak position is an application force of 10 N and the low leakposition is an application force of 18 N.All tests shall be performed at the high leak position.The tests inTable 1 shall also be performed at the low leak position.
5.3.4 Headset measurement repeatability and averaging
Change the first paragraph as shown:
When a headset is placed on the Type 3.3 or Type 3.4 ear simulator HATS, the receiver results may varyfrom trial to trial due to slight variations in positioning.Relatively accurate and repeatable results can beobtained by making several measurements and averaging the results. The procedures in this clause shall befollowed for send, receive, sidetone, and overall measurements.
Change the third paragraph as shown:
The accuracy of the final results shall be considered acceptable if the standard deviation of the loudnessrating is 1 dB or less, and if the standard deviation of the frequency response is 2 dB or less from 200 10090Hz, and 1 dB or less from 1000 4000 Hz measurements meet the following criteria: For receive, thestandard deviation of loudness rating shall be 1 dB or less,and the standard deviation of the frequencyresponse shall be 2 dB or less from 200 to 4000 Hz.For send, the standard deviation of loudness ratingshall be 1 dB or less, and the standard deviation of the frequency response shall be 1 dB or less from 200 to4000 Hz. If the results of the first five trials do not meet these criteria, report the results, but label them asreduced accuracy.
Change the second paragraph as shown:Maximum acoustic output measurements shall be made on the same ear simulator and with the samepositioning and foree as test fixture used for receive frequency response measurements.For handsetsmeasured on HATS, an additional measurement with a force of l3N is required. See 5.3.2. for handsetspositioning，and 5.3.3 for headsets positioning，and 5.3.4 for headset repeatability and averaging.Telephone sets with adjustable receive volume controls shall be adjusted to the maximum setting.