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(Enlarged continuation of Question 8/12 studied in 1997-2000)
Type of question
Task-oriented, leading to new and updated ITU-T Recommendations.
Background
Since 1988 significant progress was made in testing technologies, e.g.
HATS, complex test signals and analysis techniques. Furthermore modern
telecommunication devices (terminals) include advanced (adaptive) signal
processing capabilities e.g. ambient noise cancellation, echo control, voice
controlled algorithms. Increasingly headsets are supplied, especially with
mobile terminals. For headset testing ITU-T specification P.38 is available
since 1988 which needs updating. The question should study impact of this
processing and reflect modern testing possibilities in the test setups for
handset and headset terminals.
Text of the question
considering
a) that significant progress was made over the last years in testing
technologies;
b) that new types of artificial ears and a head and torso simulator
(HATS) have been introduced into the P-Series Recommendations for measuring
the characteristics of telephones;
c) that proposals were made in the 1997-2000 Study Period for applying
handsets of various designs to HATS in Annex D and E to Recommendation P.64;
d) that working places (e.g. call centers) are increasingly equipped with
headsets for professional use;
e) that terminals having substantially different performance
characteristics (e.g. different headset and handset characteristics,
wideband) are gaining acceptance in the marketplace;
f) that terminals are getting increasingly more complex signal processing
and telecommunications terminals having non-linear input/output
characteristics are available and increasingly sophisticated methodologies
need to be applied in their characterization,
the following questions should be studied:
1) What changes are required to update Recommendation P.38?
2) How may the use of the new types of artificial ears specified in
Recommendation P.57 and of HATS be incorporated into P-Series
Recommendations concerning the determination of headset characteristics
also taking into account �binaural� headsets?
NOTE 1 - This Question is intended also to include consideration of
measuring methods for determining the sensitivity vs. frequency
characteristics and loudness ratings of telephony equipment not specifically
covered by other Questions (e.g. sidetone, hearing aids, including
wideband).
3) Which of the recommended test signals and test methods can be
applied for enable the determination of sensitivity/frequency
characteristics and loudness ratings for handsets and headsets having
non-linear input/output characteristics?
NOTE 2 - Recommendation P.501 recommends several test signals that
may be helpful in the study of this part of the Question, Recommendation
P.502 may give input to analysis techniques.
4) What testing methodologies are required in order to adequately
test wideband handset and headset terminals?
5) What testing methodologies are required in order to adequately
test complex terminals evaluated with the aim of their consolidation and
harmonization.
Objectives and schedule
Revision of relevant P-Series Recommendations and creation of a new
P-Series Recommendation will be completed within the Study Period.
Relationship with other Study Groups
None.
Relationship with other Standardization Organizations
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