Seigou Yasuda

Method of determining a sound localization filter and a sound localization control system incorporating the filter

A method of determining a sound localization filter for approximation of a head related transfer function. The method comprises storing a plurality of sets of initial parameters with respect to a plurality of predetermined direction angles about a front position of a listener into a memory, reading one of the sets of initial parameters from the memory in accordance with a localization shift signal, calculating an optimum filter parameter based on the read initial parameters, the optimum filter parameter needed to approximate desired frequency characteristics of the head related transfer function, determining filter coefficients of the sound localization filter based on the optimum filter parameter and supplying the determined filter coefficients to a coefficient buffer provided for the sound localization filter.

Speech recognition system including interrupt scheme that avoids operational and interfacing conflicts

A speech recognition system in which speech information inputted from a microphone is recognized and a speech signal corresponding to the speech information is generated and converted into a set of characters equivalent to keystroke information normally inputted from a keyboard, the set of characters being supplied to a keyboard buffer, so that an application program running on a computer system executes a desired job. The speech recognition system comprises a first interrupt processing part which, after receiving an interrupt signal due to a depression of a key on the keyboard, checks that information within the keyboard buffer accords with a first predefined keystroke code, turns a first flag ON only when the information accords with the first predefined keystroke code and terminates a first interrupt procedure, and a second interrupt processing part which, after the first interrupt routine is terminated, enables a second interrupt into operation of the application program only when the first flag is turned ON, so that a speech information input procedure is started to provide the keystroke information thus recognized.

Standard pattern comparing system for eliminating duplicative data entries for different applications program dictionaries, especially suitable for use in voice recognition systems

A standard pattern comparing system recognizes a data by comparing the data with a standard pattern registered in a dictionary, a plurality of kinds of data being supplied to the standard pattern comparing system. The standard pattern comparing system has a plurality of dictionaries including a plurality of normal dictionaries and one master dictionary. All standard patterns stored in each normal dictionary and some of the standard patterns stored in the master dictionary corresponding to one kind of data. There being no duplicate standard pattern included in more than two dictionaries, and each standard pattern included in the master dictionary being commonly used for at least more than two normal dictionaries to correspond to an arbitrary kind of data. The present invention is especially useful for a voice recognition system in which a speaker dependent voice recognizer is used for a personal computer which manages a plurality of application programs. A user of the voice recognizer does not have to register some duplicate words commonly used for at least more than two application programs because of the master dictionary.

Methods for forming reference voice patterns, and methods for comparing voice patterns

A method for forming a reference voice pattern to be stored in a library for use in identifying an unknown input sound. The method comprises the steps of inputting a first sound pronounced for a particular letter combination by a speaker to form a first voice pattern, the first voice pattern represented by a sound energy level as a function of time; examining the first voice pattern to determine whether or not an intermediate voiceless interval is present within a predetermined time period at least from either a beginning or terminating end of the first voice pattern; repeating the inputting and examining steps for a second sound; combining the first and second voice patterns to define the reference voice pattern, wherein, if either of the first and second voice patterns has a voiced portion in the predetermined time period and the other of the first and second voice patterns does not have a corresponding voiced portion in the predetermined time period, the combining step comprises adding the voiced portion to said other of the first and second voice patterns.

Speech recognition processors using fuzzy pattern matching

A set of LSIs for speech recognition using binary time spectrum pattern (BTSP) and pattern matching based on fuzzy theory (fuzzy pattern matching) is described. The set offers both speaker-dependent and -independent voice-recognition capabilities by changing the external program ROM. In the speaker-dependent case it has up to 1000 in the vocabulary (recognition rate 95%), while in the independent case it has a 120-word vocabulary (recognition rate 92%). The set consists of two processors: one extracts voice features and generates BTSPs, the other has a 16-bit CPU core for recognition and a unit for calculating similarity. The LSI set needs external ROM and RAM. The former stores recognition, control, and other application programs while latter stores voice templates.<<ETX>>