Committed to connecting the world


Question 9/12

Question 9/12 – Perceptual-based objective methods for voice, audio and visual quality measurements in telecommunication services
(Continuation of Question 9/12)


The work of this Question will focus on objective methods for evaluating quality parameters in telecommunication scenarios. Primarily, the methods under study should concentrate on user-perceived quality characteristics. Consequently, these methods and algorithms include perceptual approaches. They model results and procedures, which are applicable in subjective tests. So that subjective procedures will get an objective counterpart by using same scaling and basic procedures.

An example for that is the successful standardization of Recommendations P.862, P.862.1, P.862.2, P.862.3 and the P.863, perceptual based methods those models objectively Listening Only Tests with Absolute Category Rating for the evaluating of the Listening Speech Quality according to Recommendation P.800. A no-reference counterpart of P.862 was approved as P.563.


This Question will extend the objective evaluation of Listening Quality – the main issue up to now – to other quality aspects of voice telephony like talking quality and wideband / super-wideband speech. Under consideration of new generation telecommunication services, also other media than speech like music and video as well as speech intelligibility should be taken into account.
Furthermore, the evaluation of transmitted noise – especially after processing by noise suppression systems – should be covered by the work of this Question. This Question analyses and recommends also methods, metrics and procedures for statistical evaluation, qualification and comparison of objective quality prediction models.
This Question will also continue and finalize the ongoing work on P.OSI, P.ONRA, P.AMD and P.SPELQ.
The following Recommendations, in force at the time of approval of this Question, fall under its responsibility:
P.563, P.862, P.862.1, P.862.2, P.862.3, P.863, P.1401



Study items to be considered include, but are not limited to:

  • P.863 will be supplemented by a User's Guide to P.863 that gives information for practical use of P.863 and results to be expected.
  • An already defined work item in the previous study period is the objective assessment of talking quality. Therefore at first a reliable subjective test method has to be established. In a second step, an objective model can be developed.
  • In addition to the existing objective models like P.862 or P.563 that are producing single numbers describing the overall quality; a need for additional information about possible quality degradations and quality dimensions are requested by the market. This is studied under P.AMD but has also to be studied in no-reference single ended approaches such as P.563 or P.SPELQ.
  • Furthermore, the objective assessment of audio signals such as music transmitted over telecommunication links like cell networks or VoIP should be investigated.
  • The objective rating of the annoyance of noise and residual noise – especially by processing by VQE's – in voice communications has to be investigated. Here a close relationship to the recently approved subjective method P.835 is given. A study item P.ONRA is already launched in this Question.
  • The determination of the quality of synthesised speech in an instrumental way, e.g. using the objective perceptual methods, is an interesting topic in this Question.
  •  In addition to the voice related topics a request for evaluating of objective video assessment models was registered. This topic should be restricted to typical video applications in telecommunication services. That requires a restriction to low bit rate video coding as well as limited image sizes like used in mobile phones and PDA's. Here a close partnership to VQEG is established.
  • This Question analyses and recommends methods, metrics and procedures for statistical evaluation, qualification and comparison of objective quality prediction models. These statistics can be applied to objective prediction models which can be translated to an estimated subjective judgment of a dedicated subjective test procedure. This Question discusses frameworks, metrics and example procedures for those statistical analyses and reporting.
  • Considerations on how to help measure and mitigate climate change.


Tasks include, but are not limited to:

  • Maintenance and enhancement of P-series Recommendations with regards to objective quality testing methods and perceptual models.
  • It is anticipated that new Recommendations on objective evaluation of:
    • User's Guide to P.863
    • Objective evaluation of Noise Reduction Systems (P.ONRA)
    • Objective estimation of individual quality dimensions (P.AMD)
    •  Objective prediction models for speech intelligibility (P.OSI)
    •  A new no-reference model for listening quality prediction in mid-pint and end-point applications (P.SPELQ)
    • Objective prediction of Talking Quality
    • Annoyance models for noise in voice communications
    • Non-Speech signals in voice-band telecommunication scenarios (e.g. music)  can be produced in the 2013-2016 study period.
An up-to-date status of work under this Question is contained in the SG 12 work programme



  • P-series, G.100- and G.1000-series
  • 3/12, 4/12, 6/12, 7/12, 11/12, 14/12, 15/12, 16/12
Study Groups
  • ITU-T SG 9, SG 16
Standardization bodies