What is a voice chip, generally used in what products?

Voice chip refers to the IC that can store and control the playback of voice, also known as sound chip, audio ic. According to the output mode of the voice chip can be divided into two categories, one is the PWM output mode, a class of DAC output mode, PWM output volume can not be continuously adjustable, can not be connected to an ordinary amplifier, the majority of the voice chip on the market is the PWM output mode. Generally used in smart home and security areas such as smart doorbells, alarms and other products.