Abstract: An electronic hand-held, talking learning aid is disclosed. The learning aid includes a MOS speech synthesizer chip having an active surface area on the order of 45,000 square mils. The disclosed speech synthesizer chip includes a digital lattice filter, a voiced/unvoiced excitation circuit, a speech parameter interpolator, an input parameter decoder, a digital-to-analog converter and associated timing circuits. The learning aid is also provided with a microprocessor which functions as a controller for controlling the operation of the unit. A small speaker is driven by the digital-to-analog converter on the speech synthesis chip and a keyboard and display device are strobed by the microprocessor controller. Features include modes in which a speech synthesizer recites instructions or questions to the operator who must properly respond.

Abstract: An electronic handheld talking translator including a speech synthesis integrated circuit device. The speech synthesis integrated circuit device includes a digital filter, a voiced/unvoiced excitation circuit, a speech parameter interpolator, an input parameter decoder, a digital-to-analog converter, a speaker and associated timing circuits. A non-volatile memory stores digital data representative of the correct spellings of selected words in a foreign language and the model vocal tract control data necessary to control the speech synthesis circuit in a manner to cause the selected words to be audibly pronounced by the translator.

Abstract: A speech synthesis circuit is provided with a variable frame length data converter and the speech synthesizer is preferably integrated on an integrated circuit chips. The variable frame length data converter reduces the amount of data required to synthesizer human speech at a given quality level. Preferably, a full frame of data includes, a pitch parameter, an energy parameter, a repeat bit and a plurality of speech coefficients. Each parameter or coefficient has a preselected length, but each frame has a variable number of parameters or coefficients associated therewith. The parameters and coefficients are encoded and a particular code of the pitch parameter indicates that the speech is to be unvoiced. An unvoiced frame includes fewer coefficients that a voiced frame and the converter detects this particular pitch parameter and automatically sets the unsent coefficients to zero.

Abstract: A system using a digital filter for generating complex waveforms, such as human speech. The filter has a multiplier, an adder coupled to the output of the multiplier and various delay circuits coupled to the output of the adder. A latch memory is coupled to the output of one of the delay circuits. Switching circuits are provided for the output of the delay and the latch memory to inputs of the multiplier and the adder to selected times. Coefficients of the filter are preferably stored in a memory coupled to another input of the multiplier. The excitation signal is coupled to the adder in one embodiment and to the multiplier in another embodiment.

Abstract: A system incorporating an integrated circuit device or chip which digitally synthesizes human speech using a linear predictive filter. The linear predictive filter comprises a single filter stage only which contains a single multiplier for selectively multiplying a plurality of coefficients, initiating the multiplication of one coefficient at a time, by using a feedback loop with multiplexing techniques so as to input multiplexed signals to the multiplier--as contrasted to a cascade of filter stages. Thus, the single multiplier of the linear predictive filter is utilized repetitively to provide the calculations required. The system also includes a memory for storage of digital filter coefficients, a controller for selectively accessing the coefficients, and a speaker for generating audible sounds.

Abstract: A speech synthesis circuit is provided with a variable frame length data converter and the speech synthesizer is preferably integrated on an integrated circuit chips. The variable frame length data converter reduces the amount of data required to synthesizer human speech at a given quality level. Preferably, a full frame of data includes, a pitch parameter, an energy parameter, a repeat bit and a plurality of speech coefficients. Each parameter or coefficient has a preselected length, but each frame has a variable number of parameters or coefficients associated therewith. The parameters and coefficients are encoded and a particular code of the pitch parameter indicates that the speech is to be unvoiced. An unvoiced frame includes fewer coefficients that a voiced frame and the converter detects this particular pitch parameter and automatically sets the unsent coefficients to zero.

Abstract: A method of communicating Digital Speech Data to a speech synthesis circuit. The data is compressed to on the order of 1000-1200 bits, per second for normal human speech. The speech synthesis circuit utilizes linear predictive coding techniques for producing high quality speech or other sounds.The data is preferably stored in a memory which is coupled to the speech synthesis circuit. The data has variable frame lengths; in the disclosed embodiment, four different frame lengths are described having frame lengths from four bits to forty-nine bits. The memory stores the variable frame length data and communicates the same to the speech synthesis circuit in response to certain control signals.

Abstract: A digital filter of the type which may be used in circuits for generating complex waveforms, such as human speech. The filter has a multiplier, an adder coupled to the output of the multiplier and various delay circuits coupled to the output of the adder. A latch memory is coupled to the output of one of the delay circuits. Switching circuits are provided for the output of the delay and the latch memory to inputs of the multiplier and the adder to selected times. Coefficients of the filter are preferably stored in a memory coupled to another input of the multiplier. The excitation signal is coupled to the adder in one embodiment and to the multiplier in another embodiment. In either embodiment, the digital filter may be implemented on a single integrated circuit chip.

Abstract: Disclosed is an integrated circuit device or chip which digitally synthesizes human speech using a linear predictive filter. This device may be implemented using conventional processing techniques. For instance, when implemented in conventional P-channel MOS technology, the disclosed device or chip has an active area of approximately 45,000 square mils.