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Publication of BE378432ApublicationCriticalpatent/BE378432A/xx
H04M9/00—Arrangements for interconnection not involving centralised switching
H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
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Engineering & Computer Science
(AREA)
Signal Processing
(AREA)
Sub-Exchange Stations And Push- Button Telephones
(AREA)