Electronic noise attenuation method and apparatus for use in effecting such method

• Main Authors: KINOSHITA; AKIO, MIZUNO; KEIICHIRO, MIURA; TANETOSHI, TAKAHASHI; MINORU, HAMADA; HAREO, SATO; NORIHARU
• Format: Patent
• Language: English
• Published: 15.03.1994
• Edition: 5
• Subjects: ACOUSTICS; ACOUSTICS NOT OTHERWISE PROVIDED FOR; BASIC ELECTRONIC CIRCUITRY; DEAF-AID SETS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING,NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; MUSICAL INSTRUMENTS; PHYSICS; PUBLIC ADDRESS SYSTEMS; RESONATORS; SOUND-PRODUCING DEVICES; TESTING

A method for electrically attenuating a noise in an area for a sound wave to be propagatable in a three dimensional direction by making up a drive signal from the information on the noise and previously given filter coefficients by use of an adaptive digital filter and then generating an additional sound wave in accordance with the drive signal for cancellation of the noise. In the electric noise attenuation method, there are provided in a given region for noise attenuation, first and second error sensor groups for detecting an interference sound wave produced between the noise and additional sound wave, at a sampling time, a filter coefficient is calculated based on the information relating to the first error sensor group, at the next sampling time, another filter coefficient is calculated based on the information relating to the second error sensor group, and these operations are repeatedly executed sequentially for each error sensor to thereby update the filter coefficient of the adaptive digital filter.