Abstract: A system is provided that trains a speech processing device to recognize any spoken language. The speech processing device is trained by receiving a group of speech frames (302). The group of speech frames is grouped into a group of segments (304). A model of each of the segments is created (306) and the segments are compared (308). The segments are grouped into clusters based on comparisons of the segments (310). A model for each of the clusters is built (312). The built cluster models enable the labeling of segments from speech in the language. Labeled segments (i.e., recognizer output) may be used to train topic classifiers. Speech topics may be classified on the basis of the generated labeled segments.

Abstract: A password controlled switching system and method of operation for enrolling and storing passwords identifying lines and trunks of the switching system denied access thereto by other lines and trunks and which is operable upon a match of a calling party command with an enrolled and stored password for selectively interconnecting the calling party via a line with ones of the restricted lines and trunks.

Abstract: Superior performance, better tracking, and stability of an adaptive predictor are realized by employing a so-called high order (eighth) prediction filter and by updating the filter coefficients in accordance with an algorithm based on the sign of a reconstructed signal sample (s.sub.q (k)) multiplied by a quantized version (e.sub.q (k)) of a differential error signal normalized by an expected magnitude of the reconstructed signal sample.

Abstract: An improved Adaptive Predictor Circuit for use in an Adaptive Differential PCM Coding system (ADPCM) uses tap coefficient values to determine adaptation rate. The stability margin of a fourth order adaptive predictor is improved by dynamically changing the adaptation speed of the tap coefficients (a.sub.i) depending upon the location of the poles with respect to the unit circle in the Z domain. The predictor comprises a 4-tap adaptive transversal filter (31) and a coefficient update circuit (32) for the same. The output of the coefficient update a.sub.i (where i=1,2,3,4) is also delivered to a logic circuit (34) which calculates a predetermined function of the tap coefficients. If the calculated function is greater than a given threshold, an input speech or voiceband data signal is concluded and a normal speed of adaptation is permitted. However, if the calculated function is less than the threshold, a narrowband signal is indicated and the adaptation speed is substantially reduced.