Call Today 716.688.4675

G.165 Echo Canceller Software

Line Echo Cancellation Diagram

G.165 echo cancellers standardize performance and ensure network interoperability

VOCAL’s  G.165 Echo Canceller software is fully compliant with ITU G.165 and optimized for execution on ANSI C and leading DSP architectures.  Our echo cancellers have been rigorously tested, meeting ITU compliance tests as well as our own. G.165 Echo Cancellation algorithm is available standalone, as part of an embedded library, or with a VoIP stack for integration with developer applications. Custom solutions are also available to meet application specific requirements.

download brochure

Our voice software is optimized for DSPs and conventional processors from TI, ADI, ARM, AMD, Intel and other leading vendors. Our experts can provide a custom, optimized line echo cancellation solution to meet most types of processing and acoustic environment requirements. Please contact us for more information or to arrange a demonstration.

G.165 Echo Canceller

The ITU G.165 Recommendation was initially developed to standardize line echo canceller performance and ensure network interoperability. Unfortunately, the focus on band-limited noise measurement and testing often resulted in unsatisfactory speech performance. As a result, it was superseded by the ITU G.168 Recommendation and subsequent addenda. In actual practice it is more beneficial to use a stripped subset of the G.168 implementation to satisfy most echo cancellation requirements rather than a G.165 Line Echo Canceller.

VOCAL has developed a variety of echo cancellation modules and solutions, including acoustic echo cancellers (AEC), line echo cancellers (LEC), and digital network echo cancellers (DNEC). Our line echo cancellers are used in millions of installations world-wide, including the public telephone system, a variety of VoIP products, as well many other types of manufactured items.


  • Fully compliant with ITU G.165 Recommendation
  • Rapid convergence
  • Subjective low returned echo level during single talk
  • Low divergence during double talk
  • Configurable tail length up to 128 ms
  • Utilizes Normalized LMS (NLMS)
  • Low echo return level during single talk
  • Double talk detector avoids divergence during double talk
  • Tone detector and hold release logic
  • Non linear processor (NLP) with Comfort Noise Generator (CNG)
  • Supports user callable functions

G.165 Echo Canceller Test Compliance

  • Compliant with Test No. 1 Steady state residual and returned echo level test
  • Compliant with Test No. 2 Convergence test
  • Compliant with Test No. 3 Performance under conditions of double talk
  • Compliant with Test No. 4 Leak rate test
  • Compliant with Test No. 5 Infinite return loss convergence test
  • Compliant with Test No. 6 Nondivergence on narrow-band signals
  • Compliant with Test No. 7 Nonconvergence of echo cancellers on mono or bifrequency signals transmitted in a handshaking protocol
  • Compliant with Test No. 8 Overload test for Type A and Type D cancellers

More Information



VOCAL’s G.165 Echo Canceller software is available for the following processor and DSP platforms.

  • Texas Instruments – C6000 (TMS320C62x, TMS320C64x, TMS320C645x, TMS320C67x), C5000 (TMS320C54x, TMS320C55x), OMAP3 (OMAP35x, OMAP36x), OMAP4 (OMAP44x), Sitara (AM37x)
  • Analog Devices – Blackfin, TigerSHARC, SHARC
  • ARM – ARM7, ARM9, ARM9E, ARM10E, ARM11, StrongARM, ARM Cortex-A8
  • PowerPC
  • MIPS – MIPS32, MIPS64, MIPS4Kc
  • Intel / AMD – x86, x64 (both 32 and 64 bit modes)

Please contact us for other supported platforms.

Operating Systems

VOCAL’s G.165 Echo Canceller software is available for the following Operating Systems:

  • Android
  • iOS
  • Unix,  Linux, uClinux
  • Microsoft Windows ACM / RTC / CE / Mobile
  • Symbian,
  • Mac OS
  • BSD
  • VxWorks
  • Integrity

Please contact us for other supported Operating Systems.

VOCAL Technologies, Ltd.
520 Lee Entrance, Suite 202
Amherst New York 14228
Phone: +1-716-688-4675
Fax: +1-716-639-0713