This part is a kind of semiconductor called BL34018.

Function of this product has high quality hands free speakerphone system.

Manufacturers : SHANGHAI BELLING

Image and pinout :

Some of the text within the PDF file :

BL34018 1. GENERAL DESCRIPTION The BL34018 Speakerphone integrated circuit Incorporates the necessary amplifiers ， attenuators ， and control functions to produce a high quality hands free speakerphone system． Include are a microphone amplifier， a power audio amplifier for the speaker， transmit and receive attenuators，a monitoring system for background sound level，and an attenuation control system which responds to the relative transmit and receive levels as well as the background level．Also included are all necessary regulated voltages for both internal and external circuitry， allowing line-powered operation (no additional power supplies required)．A chip select pin allows the chip to be powered down when not in use．A volume control function may be [ ... ]

BL34018 PDF Datasheet Download