COMPRESSION AND/OR EXPANSION SYSTEM AND CIRCUIT

• Main Authors: TAKAHASHI N,JA, FUJITA Y,JA, NISHIKAWA K,JA, ISHIGAKI Y,JA, ITOH Y,JA
• Format: Patent
• Language: English
• Published: 05.03.1974
• Subjects: BASIC ELECTRONIC CIRCUITRY; CONTROL OF AMPLIFICATION; ELECTRICITY

A compression and/or expansion system comprises fixed frequency characteristic changing means having a specific fixed frequency-response characteristic which increases or decreases the level of an input signal in a predetermined frequency band. A variable frequency characteristic changing means has a characteristic which varies so that it approaches a characteristic complimentary with the characteristic of the fixed frequency characteristic change means as the level of the input signal becomes larger and approaches a flat characteristic as the level of the signal becomes smaller. The signal is effectively compressed or expanded according to its level by passing through the fixed and variable frequency characteristic change means.