DIGITAL SPEECH offers  Line echo cancellers  for telephone applications and VoIP and VoP gateways. Line echo is created by telephone hybrid which transforms 4 wire line to 2 wire line. Usually there are two hybrid in the telephone line. One corresponds to near end terminal and one corresponds remote terminal. The DIGITAL SPEECH echo cancellers can remove near and far echo. Additionally DIGITAL SPEECH line echo cancellers can remove residual acoustic echo from mobile phone (for example from DECT phones). LEC for client side telephony (Terminal LEC) has special features for seamless connection with DIGITAL SPEECH acoustic echo canceller. It allows exclude howling (Larsen effect) in hands-free phones and conferencing equipment. Enhancement gateway LEC (Network LEC) can very effective works in networks with VoIP segments. It has very long maximal echo path (up to 256ms), protection against to non-linear distortions and background noise, the special features for fast reconvergence after echo path change. Additionally it has internal noise suppressor. All cancellers have internal tone detector which prevents convergence to local minimum.

DIGITAL SPEECH offers Line echo cancellers for the following applications

Terminal LEC is intended for general PSTN phones, teleconferencing systems, analog telephone adaptors, payphones and other devices using LEC on client side.

Network LEC was developed for gateway application using LEC on server side.

• Fast convergence
• Fast reconvergence after echo path change
• Robustness in respect to background noise and non-linear distortion
• Maximal echo path up to 256ms
• Robust double talk detector
• Non-linear processor
• Comfort noise generator matched with original noise
• Internal tone detector preventing convergence to local minimum
• Meets G168-2004 requirements
• Reliable work in networks with VoIP segments