TestingTask Force T021:
Characterization of the New ETSI speech codec on subjective
Test data bases - CNET step 2
Who we are:
Pomy, Focus Infocom Gesellschaft für
Informatik und Telekommunikation mbH, firstname.lastname@example.org
STF Experts: Jan
Mesaqin.com s.r.o (Ltd.), email@example.com
Markus Schnell, Fraunhofer Institut für Integrierte
Maximilian Schlegel, Fraunhofer Institut für Integrierte
What we do
are two more topics which had not
been included in TTF T005, because they could only be initiated
after it was
confirmed by TTF T005 that the New ETSI Speech Codec (LC3plus)
requirements set out in TS 103 624. This has now been confirmed by
subjective tests conducted by the TTF T005 team.
the proposed activity under
this new TTF consists of the following two topics, which are
context of the New ETSI Speech Codec:
According to TS 103 624
the subjective tests shall be followed by a verification with the
method ITU-T P.863.
NOTE: At the time when TS 103
drafted, there was the expectation that these tests would be
provided by a
specific STQ member at no extra cost. However, that company is no
member of ETSI and will not provide these tests.
For the purpose of
inclusion of the
New ETSI Speech Codec in transmission planning, ITU-T SG12 is
to provide information on the so-called Equipment Impairment
of the New ETSI Speech
Codec for future inclusion in ITU-T G.113.
-Factors are a characterization of the impact of speech codecs on
quality on a psychological scale; their values are available for all
which are of relevance in modern networks and terminals.
In order to fully establish the New ETSI Speech Codec
knowledge about the
Ie -Factors is required and it
highly promotional for ETSI to provide the international community
Equipment Impairment Factors for transmission planning for the New
Codec for all three instances of the Transmission Planning with the
namely narrowband (NB), wideband (WB) and fullband (FB).
In order to provide the values for FB, a new methodology will have
established; this can be done based on existing work in the field,
like (1) ,
(2), (3) or (4)
the Ie factor
has been derived for the OPUS codec
work to be executed
Objective assessment of the
subjective test result already produced by TTF T005.
This cross check shall verify that the test results on the New ETSI
Codec (LC3plus) show no statistically significant differences
subjective or objective assessment.
Determination of the
Impairment Factors for the different bandwidth modes of the codec.
Test plan definition:
As the exact procedure for FB Ie is currently not standardized, it
to design and agree upon the complete test procedure. Also test
plans for the
determination of NB and WB Ie are to be compiled based on ITU-T
P.834 and P.834.1.
test material, recordings:
To derive the Ie parameter, a combination
of subjective and
objective tests is needed. These tests will require a set of test
be used as input materials for both test types.
As ITU-T C-208 shows a discrepancy between subjectively (P.833.1)
Ie values, Ie
will be derived based on both objective and
using POLQA (ITU-T P.863)
conclusion and derivation of one single
value per bandwidth mode, if possible.
For more details, see
Terms of Reference
Why we do it
Ie -Factors for transmission
the New ETSI Speech Codec (LC3plus) will be available, and the codec
established internationally outside ETSI. This has to be seen in the
that for the OPUS codec
Ie - values are already known and
can be used
for network planning purposes.
The LC3plus codec technology is also contributed to
Bluetooth providing a significant improvement to previous
order to provide the technical benefits also to groups outside ETSI
activity is also performed.
How we do it
The TTF experts are
remotely from their locations (Germany, Czech Republic). The
will be performed in MESAQIN.com listening laboratory premises in
native English speakers.
information will be added to TS 103 624:
the speech data bases used for the subjective tests using POLQA
new Annex to TS 103 624
Factors for the different bandwidth modes of the codec: new Annex to
TS 103 624
After approval by ETSI STQ, the revised version(s) of TS 103 624 will be
available to the general public.
STQ approval is
end of February 2024.
needed, please send an email to
This information is based upon STF/TTF working
The views expressed do not necessarily represent
position of ETSI in the context.