The ML22808/ML22804/ML22802-xxx are speech synthesis LSI devices that have P2ROM for storing voice data. The voice output component has an ADPCM2 decoder to enable high speech quality, a D/A converter, and a low-pass filter. It is easy to configure a speech synthesizer by connecting a power amplifier and a CPU externally. The ML22808/ML22804/ML22802-xxx allow selection of a playback method from among the 8-bit PCM, non-linear 8-bit PCM, 16-bit PCM, and 4-bit ADPCM2 algorithms and enable volume control. The ML22808/ML22804/ML22802-xxx, supported by the ROM codes, are the products in which written speech data is included. The ML22P808/ML22P804/ML22P802 are OTP products in which speech data can be easily written by the user using a dedicated writer. These devices are suitable for applications in developing products, manufacturing of a wide variety of products in small quantities, and requiring quick turn around.