TGSpeechBox

TGSpeechBox is a high-quality speech synthesizer that works as a system voice with VoiceOver and as a standalone text-to-speech app.
Features:
• 26 languages with natural-sounding speech
• Full VoiceOver integration — use as your primary system voice
• 7 voice presets plus YAML-defined voice profiles
• Deep engine tuning: pitch mode, voice tone, formant sharpness, inflection, tremor, breathiness, and more
• Phoneme editor: fine-tune individual speech sounds with live preview
• Pronunciation dictionary: add custom word pronunciations with IPA override support
• Stress, compound, and character dictionaries for advanced control
• Export and share your customizations
• Adjustable sample rate (11025–44100 Hz)
• Rate override and rate boost for VoiceOver
• Language lock: keep your preferred language regardless of system setting
• Runs entirely on-device — no internet required, no data leaves your phone
TGSpeechBox uses a Klatt-style formant synthesis engine with eSpeak-ng for phoneme generation. It is open source under the MIT license.
Built by a blind developer, designed for accessibility from day one.