The Silicon Vocal

An analog VLSI circuit model of the vocal tract is described. The vocal tract is acoustically modeled as a series of uniform cross-section tubes concatenated end-to-end. Each section of tube is modeled as an RLC circuit whose element values are determined by its area and length with the current and voltage corresponding to volume velocity and pressure in the tube. An analog VLSI circuit is described that these same equations. With the proper vocal tract connguration, the circuit has been shown to simulate several vowels. Spectral analysis of the simulated circuit output reveals that the rst three formants are in the same range as the corresponding human vowel formants. The silicon vocal tract will form the basis of a completely integrated analog VLSI articulatory speech synthesizer. The VLSI cylindrical section analog circuit has been designed, simulated and submitted to MOSIS for fabrication in a 2m CMOS process.