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The diagram below gives you an example of the
results of a typical measurement with OPTI-
COM's ECHO tool after the data was evaluated
with a spread-sheet program. The diagram is
divided into two distinct areas separated by an
extrapolated and approximated talker echo toler-
ance curve derived from the ITU-T standard
G.131. All echoes (peaks) that do not reach out of
50
40
30
20
10
0
0
80 100 240 320 400 480 500 640
Unacceptable Echo Area
ERL vs. Delay
Specifications
Advanced Perceptual ECHO Measurement Tool
Functionality
• Echo Return Loss (ERL); echo attenuation in
dB
• ERLs and echo delays for multiple echoes
• Perceptual estimation of echo annoyance,
using subjective analysis results as stated in
ITU-T G.131
• Additional measurement outputs for compre-
hensive analysis
• Narrowband and Wideband operation
• Real speech signals for analysis
Input
• Two audio signals required:
Reference speech signal and echo signal
• 16 bit linear audio sampled at
8kHz and 16kHz
• 6 to 20 seconds in length
PEVQ™, 3SQM™ and the OPTICOM logo are registered trademarks of OPTICOM GmbH; the 'single-sided speech quality measure' and
'the perceptual quality experts' are trademarks of OPTICOM GmbH. This information may be subject to change.
All brand and product names are trademarks and/or registered trademarks of their respective owners.
All rights reserved. Copyright © 2005 OPTICOM GmbH – www.opticom.de
the blue area are generally likely to be perceived
as annoying while all peaks that reach into the
orange area are sufficiently attenuated and are
tolerable – if perceived at all. Here, easily three
echo peaks can be identified which lie in the blue
area of the diagram. These echoes are too loud
to be negligible and are very likely to be per-
ceived as annoying by a customer.
Delay in ms
Acceptable Echo Area
Tolerance Curve
Output
• ERL / Delay for multiple echoes
• Statistical information of the echo analysis,
e.g. ERL / Delay histogram
• Comprehensive evaluation of the echoes
influence on conversationally perceived
quality
Platform
• Windows
• Linux
About OPTICOM
With PSQM, PESQ and PEAQ,
OPTICOM GmbH, the pioneer
in perceptual quality testing
has been providing three
international world-class
standards for voice and audio
quality measurement since
its foundation in 1995. With
their new single-sided
speech quality measure
3SQM
, a joint development
™
with partners, the perceptual
experts from Germany now
presented their fourth ITU
standard. At its 10th anniver-
sary, the presentation of the
new PEVQ™ video measure
leverages the company's
huge experience towards the
multimedia testing domain.
Recognized an industry refer-
ence, OPTICOM's OPERA
voice/audio quality test tools
are available to users world
wide. And while specialized
on OEM customers in particu-
lar, the directory of OEM
licensees today reads like the
'Who-is-Who' of the
Telecoms industry. OPTICOM
is a privately held company
located in Erlangen, Germany.
Sales Contacts:
OPTICOM GmbH
Nägelsbachstraße 38
91052 Erlangen, GERMANY
Phone: +49-91 31 / 5 30 20 - 0
Fax:
+49-91 31 / 5 30 20 - 20
info@opticom.de
www.opticom.de
North America:
Telchemy Inc.
Phone +1-770-614-6944
JDSU - Acterna U.S.
Phone +1-301 353 1560 2850
Europe, Latin America,
Middle East & Africa,
Asia Pacific, CIS Countries:
JDSU - Acterna
Germany GmbH
Phone: +49-7121 86 2222
Through our distributor net-
work, we are represented in
more than 80 countries. To find
your local sales office, please
contact info@opticom.de
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