Sp-3-4350. 120-rv3 (to become ansi/tia-470. 120-C) Draft 22a ast ballot Comments with track changes on Telecommunications Telephone Terminal Equipment Transmission Requirements for Analog Speakerphones
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- Receive Loudness Rating (Handset)
- Sidetone Masking Rating (Handset)
Send Loudness Rating (Handset):Band 17 SLR = - 57.1 log10 10(0.1 * 0.175 * (SMJ – Wsi – Ks )) i = Band 4 where:
Band 17 RLR = - 57.1 log10 10(0.1 * 0.175 * (SJE – Wri – LE + KR )) i = Band 4 where:
i Frequency bands from Table 1 of ITU-T P.79 (1999), bands 4-17. SJE Receive frequency response data (Sensitivity, Junction-to-Ear) in dB(Pa/V). Wri Receive weighting factor from Table 1 of ITU-T P.79 (1999), see Table B .1 LE Leakage correction is not used when using ear simulators that include leakage such as HATS. (Leakage correction is only used when the handset is sealed to a Type 1 ear. Leakage correction from Table 2 of ITU-T P.79 (1999), see Table B .1 KR Impedance sensitivity correction = 1.76 dB when 900 ohm termination is used in the measurement.
Band 20 STMR = - 44.4 log10 10(0.1 * 0.225 * (SmeST – WMSi)) i = Band 1 where:
Table B.1 – ITU-T P.79 Tables 1, 2 and 3, Weighting factors for calculating loudness ratings
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