From Roberto Forcen:
Expression Tone Generator is an ideal tool for creating impressive sound effects using the power of math. The application writes algebraic expressions using sound-related built-in functions (osc, wave, note, and tone) and allows you to hear them quickly with one keystroke. It includes a graph display for wave preview and a note/octave to frequency converter. A full set of arithmetic and logical operators and trigonometric, transcendental functions are included, enabling complex wave definition at any sample rate. Fast evaluation is achieved through an internal expression compiler, performing near C efficiency. Generated waves can be saved as WAV files. Formula files can be saved and retrieved for later use. This tool is suitable for composers, electronic musicians, sound researchers, game programmers, and anyone interested in learning more about the fascinating link between math and sound.