Abstract: A method for call back messaging is disclosed. The method allows a calling party to provide name and number information for automatic delivery to a called party in instances where the called party does not answer the incoming call, or where the line of the called party is busy. The method of the present invention may include the steps of processing an exception for an incoming call from the calling party to the called party, playing at least a first announcement to the calling party to provide the calling party an opportunity to provide information to the called party, processing information provided by the calling party, placing at least a first call to the called party to attempt to deliver the information provided by the calling party and playing at least a first message to the called party, the first messaging containing the information provided by the calling party.

Abstract: A method of evaluating the quality of speech in a voice communication system is used in a speech processor. A digital file of undistorted speech representative of a speech standard for a voice communication system is recorded. A sample file of possibly distorted speech carried by said voice communication system is also recorded. The file of standard speech and the file of possibly distorted speech are passed through a set of critical band filters to provide power spectra which include distorted-standard speech pairs. A variance-covariance matrix is calculated from said pairs, and a Mahalanobis D.sup.2 calculation is performed on said matrix, yielding D.sup.2 data which represents an estimation of the quality of speech in the sample file.

Abstract: A teleconferencing bridge simulates the auditory spatial ambience of a face-to-face conference. This bridge uses a novel binaural approach to simulate spatial ambience.