DAGA 2010 - Deutsche Gesellschaft für Akustik eV

202 DAGA 2010 Programm
Mi. 16:55 Grashof C 215 Akustische Messtechnik
Mobile Phone Performance Evaluation in Background Noise
H.W. Gierlich, F. Kettler, S. Poschen und S. Kengne
HEAD acoustics GmbH
The performance of mobile terminals in the presence of background noise
is crucial because this represents the typical use case today. This
also motivates the development and conduction of appropriate speech
quality tests. The D-value calculated from DELSM according to ITU-T
Recommendation G.111 and the ANR in a similar way represent a onedimensional
score indicating the sensitivity differences of a terminal for
speech and background noise and is typically used in telecommunication.
A more advance method, SNRI is described in ITU-T Rec. G.160. A
perceptually based method for determine the performance of terminals
in background noise is described in ETSI EG 202 396-3. For objective
performance evaluation all methods are compared for different narrowband
and wideband mobile phones. All methods are analyzed with respect
to their ability to predict quality parameters of speech in a noisy
environment. The results are discussed and conclusions about the applicability
and comparability of the methods are drawn.
Mi. 17:20 Grashof C 215 Akustische Messtechnik
Advanced Testing of Wideband Terminals
F. Kettler a , S. Poschen a , A. Raake b und S. Spors b
a HEAD acoustics GmbH; b Deutsche Telekom Laboratories, TU Berlin
Communication is migrating towards wideband transmission (50 Hz - 7
kHz). Terminals and networks are developed in order to provide a significant
step towards higher speech quality. At the same time, also standardization
bodies like ETSI, GCF and the DECT Forum are working
on new specifications for terminals. At this stage, network provisioning
and wideband terminal testing often only considers the speech codec
implementation. It is typically disregarded that speech quality is mainly
deter-mined by the acoustic interfaces and the implemented signal processing.
In order to setup appropriate speech quality measurements for
wideband terminals, existing narrowband and wideband test specifications
were reviewed and analyzed. Advanced tests such as double talk
performance measurements and quality tests in the presence of background
noise have only recently been established for narrowband terminals.
They need to be re-considered and established for wideband terminals,
too, in order to provide high quality terminals already during market
launch. Furthermore wideband requirements can typically not be extrapolated
from the narrowband case. This contribution discusses current
wideband standards and the development of new speech quality tests
and requirements for mobile and fixed wideband terminals.