Audio

Voicemod is a free real-time voice changer and soundboard available on both Windows and macOS that allows users to change their voice and add sound effects to their streams, videos, and chats.

Auphonic is an all-in-one audio post-production web tool that allows users to achieve professional quality results, with features such as automatic speech recognition, shownotes, and chapters, and can be used for free for up to 2 hours of audio each month.

Lunaverus.com offers AnthemScore, a program that can transcribe audio to MIDI and generate sheet music, available for a 30-day free trial with full features.