The Artificial Voice Type 4219 is a complete redesign of the Artificial Mouth Type 4216. It is intended for use in laboratories and quality production control, when a well defined sound source is required, and when it is more convenient to use an artificial source rather than the human voice. The Artificial Voice produces a sound field similar to the sound field from a human mouth, and also covers the frequency and pressure ranges normally produced by the human voice. it is equipped with a built-in condenser microphoneand preamplifier, which can be used with the compressor circuit of a B & K Beat Frequency Oscillator to maintain a constant sound pressure at the orifice. The characteristics of the voice make it suitable for general acoustic work, and telephone measurements.