Abstract: A method and apparatus for processing a signal to extract selected information therefrom is provided. According to the method, an input signal is converted into a sequence of data samples, and these data samples are applied sequentially through a convolver having first and second sections, the output of the first section forming the input of the second section. A data sample in the second convolver section is then compared to each data sample in the first convolver section to produce an output signal of a plurality of data points, each of the data points representative of a midpoint position within the convolver between a pair of compared data samples. This comparison step is repeated for each data sample in the second convolver section and the output signals form a histogram from which the selected information is extracted. This method may be advantageously utilized in a speech recognition process for extracting various features from an input speech signal.

Abstract: The present invention comprises a frequency responsive tactile stimulator. Selected mid-frequency and high frequency components are extracted from an input audio signal by a bandpass filter (18) and a high-pass filter (20). The outputs of these filters are transmitted through precision rectifiers (22, 24) and provided to modulate power drivers (26, 28). A random noise signal is generated by a noise generator (30) and limited to fixed length randomly distributed pulsed by a one-shot circuit (36). The random pulses are provided as the input to the power drivers (26, 28). The lower frequency power driver (26) drives a plurality of vibrators (42-48) which are spatially arranged on a transducer to cover a distinct area. The high frequency signal component modulates power driver (28) which drives two vibrators (50, 52) which are contiguously located to produce a punctate vibration.

Abstract: Voice pitch is detected by passing a speech signal from a microphone 10 through a filter array 20 to a summing amplifier 22. The summing amplifier 22 provides a composite signal of the acoustic components of the speech signal and this composite signal is input to a multiplier 26 and from the multiplier 26 to a multiplier 36 having an output connected to a comparator 42. The comparator 42 compares the output of the multiplier 36 with a hysteresis signal, then provides an output to a phase locked loop 46. The phase locked loop 46 provides a first voltage output in analog form to a bar graph display 50 and provides a square wave output that is applied to a frequency-to-voltage converter 52 for driving a digital display 54.

Abstract: A speech signal is input to a microphone (10) and applied through a signal compressor (14) to a filter array (18) consisting of a high pass channel (20), a midfrequency channel (22) and a low pass channel (24). The outputs of the filter array (18) are precision rectified in rectifiers (28), (36) and (46). The rectified signals are applied to voltage controlled power drivers (54) and (56), where the output of the midfrequency channel (22) and the low frequency channel (24) are applied to the power driver (54) and the output of the high frequency channel (20) and the low frequency channel (24) are applied to the power driver (56). The power driver (54) drives vibrators (58) and (60) and the output of the power driver (56) drives a vibrator (62). To drive the vibrators (58) and (60), a random frequency signal at the output of a one shot multivibrator (38) is amplitude modulated by the output of the midfrequency channel (22).