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| Publication: A.N. Birkett, and R.A. Goubran, "Acoustic Echo Cancellation for Hands-Free Telephony using Neural Networks", IEEE Workshop on Neural Networks for Signal Processing, Ermioni, Greece, September 1994, pp. 249-259. |
| Abstract: One of the limitations of linear adaptive echo cancellers in handsfree environments is their inability to effectively cancel nonlinearities which are generated mainly in the loudspeaker during large signal peaks. The softclipping effect encountered when large signals are applied to the loudspeaker is modeled in a neural network using a piecewise linear/sigmoid activation function. A three layer fully adaptive feedforward network is used to model the room/speakerphone transfer function using the special activation function. This network structure improves the ERLE performance by 10 dB at low to medium loudspeaker volumes compared to a NLMS echo canceller. |