Abstract: Packetized CELP-encoded speech playout with frame truncation during silence and frame expansion method dependent upon voicing classification with voiced frame expansion maintaining phasealignment.

Abstract: Noise suppression (speech enhancement) by spectral amplitude filtering using a gain determined with a quantized estimated signal-to-noise ratio plus, optionally, prior frame suppression. The relation between signal-to-noise ratio and filter gain derives from a codebook mapping with a training set constructed from clean speech and noise conditions.

Abstract: Hands-free phones with echo cancellation using dual filters, one fast adapting filter and one slow adapting filter; the choice of filters includes switching with hysteresis from recent performance, and the fast adapting filter has stepsize control to limit relative filter update energy and the slow adapting filter limits filter divergence.

Abstract: A process (111,101) of sending packets of real-time information at a sender (311) includes steps of initially generating at the sender the packets of real-time information with a source rate (s11) greater than zero kilobits per second, and a time or path or combined time/path diversity rate (d11), the amount of diversity (d11) initially being at least zero kilobits per second. The process sends the packets, thereby resulting in a quality of service QoS, and optionally obtains at the sender (311) a measure of the QoS. Rate/diversity adaptation decision may be performed at receiver (361?) instead. Another step compares the QoS with a threshold of acceptability (Th1), and when the QoS is on an unacceptable side of said threshold (Th1) increases the diversity rate (d11 to d22) and sends not only additional ones of the packets of real-time information but also sends diversity packets at the diversity rate as increased (d22).

Abstract: Hands-free phones with voice activity detection using a comparison of frame power estimate with an adaptive frame noise power estimate, automatic gain control with fast adaptation and minimal speech distortion, echo cancellation updated in the frequency domain with stepsize optimization and smoothed spectral whitening, and echo suppression with adaptive talking-state transitions.

Abstract: Hands-free phones with voice activity detection using a comparison of frame power estimate with an adaptive frame noise power estimate, automatic gain control with fast adaptation and minimal speech distortion, echo cancellation updated in the frequency domain with stepsize optimization and smoothed spectral whitening, and echo suppression with adaptive talking-state transitions.

Abstract: In one form of the invention, a process of sending real-time information from a sender computer (103) to a receiver computer (105) coupled to the sender computer (103) by a packet network (100) wherein packets (111,113) sometimes become lost, includes steps of directing (441) packets (111) containing the real-time information from the sender computer (103) by at least one path (119) in the packet network (100) to the receiver computer (105), and directing packets (113) containing information dependent on the real-time information from the sender computer (103) by at least one path diversity path (117) in the packet network (100) to the same receiver computer (105).

Abstract: Hybrid linear predictive speech coding system with phase alignment predictive quantization zero phase alignment of speech prior to waveform coding aligns synthesized speech frames of a waveform coder with frames synthesized with a parametric coder. Inter-frame interpolation of LP coefficients suppresses artifacts in resultant synthesized speech frames.