This paper presents a continuous-time mel-frequency cepstrum encoding IC using analog circuits and floating-gate computational arrays. We present the dynamics of several floating-gate computational building blocks and accompanying experimental measurements. We also present a novel approach to programmable signal spectrum decomposition, analog frequency transforms, and spectrum compaction. Experimental data is presented from circuits fabricated on a 0.5 /spl mu/m nwell CMOS process available through MOSIS. This system can act as the front-end for larger digital or analog speech processing systems.