Bleeper

"Bleeper is a sound creation tool that allows users to draw volume and pitch sequences with adjustable sound duration, waveform, and pitch range. Users can export sounds as MP3 or WAV files or save program data as text for future edits. The tool features shortcuts for various functions including play, navigate, move, edit, delete, undo, redo, copy, save, and export, and it is the official SFX creation tool for P."