A speech recognition system and method that dynamically switches between reference patterns based on training information produced under different ambient noise levels to enhance speech recognition accuracy, is presented herein. It is provided with control means which controls the optical wavelength of a laser diode 1 to a prescribed wavelength by driving a temperature control unit to control the temperature of the laser diode 1. The article may be sold at a retail store, or ordered over a telephone line or online and delivered to a home of a consumer.