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.