A near full duplex portable handset speakerphone comprises: a microprocessor; a hands-free receive register connected to the microprocessor; a hands-free transmit register connected to the microprocessor; a ROM having a speakerphone operation algorithm, the ROM-connected to the microprocessor; a first analog-to-digital converter connected to the hands-free receive register; a second analog-to-digital converter connected to the hands-free transmit register; a first programmable digital attenuator connected to the microprocessor and to a speaker; and a second programmable digital attenuator connected to the microprocessor and to a microphone, wherein near full duplex communication is achieved without digital signal processing. In another feature of the invention, the hands-free registers provide a digital representation of the speech volume in each direction to the microprocessor. The microprocessor monitors the speech signal levels, calculates digital volume comparisons in order to make speech gain decisions for optimal sound, and digitally adjusts the gains in the two speech paths to the upper half of their maximum values.

 
Web www.patentalert.com

< Electronic mail system

< Apparatus for managing a device, program for managing a device, storage medium on which a program for managing a device is stored, and method of managing a device

> Active mode line voltage regulator for ringing subscriber line interface circuit

> Line Driver apparatus

~ 00298