The I²S standard was introduced in 1986 and was revised in 1996. It is a common audio interface in most consumer electronics. I2S uses three signals for data transfer: (1) word strobe (also known as frame clock), (2) bit clock, and (3) data. The component that generates the two clocks (i.e. word strobe and bit clock) is known as the “Master.” The component receiving the clock signals is known as the slave. This interface allows the user to directly attach microphones to microprocessors without use of a CODEC, which is advantageous in some systems.