| Transmission characteristics for telephone-band (300-3400 Hz) digital telephones |
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This Recommendation provides audio performance requirements and associated testing for telephone band (300-3400 Hz) digital telephones.Requirements and test methods are specified for the major audio transmission parameters including Sending and Receiving Loudness Ratings, frequency response, noise, distortion, spurious signals, sidetone, echo path and delay.This Recommendation is only applicable to digital telephones using encoding conforming to Recommendations G.711 (64 kbit/s, PCM) and G.726 (32 kbit/s, ADPCM). Lower coding rates, for example Recommendation G.726 (16 kbit/s, LD-CELP) are still under study. |
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| Citation: |
https://handle.itu.int/11.1002/1000/3306 |
| Series title: |
P series: Telephone transmission quality, telephone installations, local line networks
P.300-P.399: Voice terminal characteristics |
| Approval date: |
1996-02-06 |
| Approval process: | TAP |
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Status: |
Superseded |
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Maintenance responsibility: |
ITU-T Study Group 12 |
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Further details: |
Patent statement(s)
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ITU-T Supplement
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Title
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Status
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Summary
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Table of contents
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Download
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P Suppl. 10 (11/1988)
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Considerations relating to transmission characteristics for analogue handset telephones
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In force
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-
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here
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here
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P Suppl. 16 (11/1988)
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Guidelines for placement of microphones and loudspeakers in telephone conference rooms and for group audio terminals (GATs)
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In force
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-
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here
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here
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P Suppl. 20 (03/1993)
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Examples of measurements of handset receive-frequency responses: dependence on earcap leakage losses
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In force
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-
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here
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here
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P Suppl. 23 (02/1998)
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ITU-T coded-speech database
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In force
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here
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here
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here
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P Suppl. 24 (10/2005)
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Parameters describing the interaction with spoken dialogue systems
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In force
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here
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here
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here
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P Suppl. 25 (01/2011)
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Parameters describing the interaction with multimodal dialogue systems
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In force
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here
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here
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here
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P Suppl. 26 (09/2017)
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Scenarios for the subjective evaluation of audio and audiovisual multiparty telemeeting quality
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In force
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here
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here
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here
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P Suppl. 28 (09/2020)
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Considerations for the development of new QoS and QoE related objective models to be embedded in Recommendations prepared by ITU-T Study Group 12
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In force
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here
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here
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here
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P Suppl. 31 (01/2025)
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Subjective quality evaluation of audiovisual communication in videotelephony services
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In force
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here
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here
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here
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