Multiport conference circuit with multi-frame summing and voice level coding

摘要

An improved conference circuit for use in a Pulse Code Modulation telephone switching system wherein a number of channels are combined so that a number of subscribers may participate in a common telephone conversation. The conference circuit is provided with a voice level coding arrangement whereby the voice level comparisons used in the speaker selection process are facilitated, and with a multi-frame coded voice level summing arrangement whereby channel switching caused by spurious noise peaks is effectively eliminated.