speech synthesizer

Eight-voice standalone synthesizer

MiniSpillage is a free professional quality drum synthesizer plugin.

The X-Poly is a VST / AU synthesizer plug-in.

Polyphonic stereo subtractive Audio Unit software synthesizer.

Low-frequency punch, saturation and sub frequency synthesizer effect.

Analyze, synthesize, and manipulate speech.

Task management with speech commands and AppleScript support.

Text-to-speech utility.

Play with OS X's text-to-speech system.

Create text-to-speech ringtones.