Speech Quality Test and Verification

What is PESQ

To obtain an accurate value or definition of speech quality, an objective measure is required. The PESQ algorithm - Perceptual Evaluation of Speech Quality - was ratified within the ITU-T recommendation P.862 in 2001. It is an openly available, internationally recognised standard for the measurement of voice quality on all telecommunications networks.

What is POLQA

Perceptual Objective Listening Quality Assessment - is the latest generation of algorithm designed to predict MOS of speech signals. POLQA®  has been standardised by the ITU as Recommendation P.863 following a four year contest, and has been rigorously tested by industry experts using many thousands of test cases. It can be used to assess modern codecs catering for narrowband, wideband and super-wideband speech dealing with the characteristics of modern codecs, wider frequencies and digitally encoded voice. Since 2011, POLQA is being adopted around the world as a successor to existing algorithms including PESQ, providing more reliable measurements, particularly in these areas:

  • 3G/4G/LTE

  • HD Voice

  • VoIP

  • Noise Reduction/
    Voice Enhancement

  • Accoustic Testing

     P.862 and PESQ Output

      p.862 and pesq output

Reference Surface


Degraded Surface

Error Surface


How PESQ and POLQA Test Voice Quality

PESQ and POLQA both quantify received voice quality using the ITU Mean Opinion Score (MOS) scale. This runs from 1 (the lowest voice quality) to 5 (the highest).

MOS scale

Listening Quality











* The MOS scale varies depending on which version of algorithm is applied e.g. PESQ and POLQA wideband run from 0 (min) to 4.5 (max) while POLQA super wideband runs from 0 (min) to 4.75 (max) 

Voice Quality Testing is evolving

PESQ has successfully evaluated voice quality for fixed and wireless networks for over a decade. However, rapid advances in speech coding techniques and noise reduction technology over the last ten years have posed certain challenges for PESQ and enabled POLQA to develop as a natural successor in speech quality testing.

Bespoke PESQ and POLQA Testing

Syntech offer a range of PESQ/POLQA testing services and consultancy. We can test multiple scenarios across a number of different circuit types and termination points. At the end of testing we will analyse and collate your results into a detailed report.

 PDF  The Benefits and Limitations of POLQA 

What Services do Syntech Provide to Assess Speech Quality?

  • We provide independent measurement and assessment of speech quality as part of
    our in-depth testing and consultancy services.

  • We can test different services and test-case scenarios incorporating different
    end-point equipment and termination points.

  • Our speech quality verification solutions can be tailored to report hundreds of different
    KPIs to suit your requirements or verify your service level agreement (SLA).
    We analyse and collate your results into meaningful reports and recommendations.

  • We can advise on methodologies and test configurations to ensure you obtain a
    statistically valid population, confidence level and error margin to meet
    your contractual requirements.

  • We are an established supplier of equipment and services in the fixed and
    mobile communications sectors.

  • Our long-term partner and UK distributor of the Malden Electronics Digital Speech
    Level Analyser (DSLA) also means we have the skills and expertise to advise and
    assist in all speech quality/voice testing areas.

Voice Quality Testing Case Study

Click here to read our Case Study of PESQ Testing for Northern Ireland Fire & Rescue Service.

To discuss your Speech Verification requirements in greater detail please contact us on 01483 443800 or email This e-mail address is being protected from spambots. You need JavaScript enabled to view it





Why Choose Syntech Pink2



Syntech Systems
Mission Hall

53a Woking Road
United Kingdom

Tel: +(44) 1483 443800
Email: info@syntechsystems.com

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