Hello,
The existing emacspeak speech server, swiftmac, is built on AVSpeechSynthesizer, and I found it a bit unresponsive, especially in fast-navigation scenarios. So I wrote nsspeaker, which continues the direction started by fastmac - a Go-based speech server that already used the more responsive NSSpeechSynthesizer, but didn't implement the full Emacspeak protocol and required a Go toolchain to build.
nsspeaker is written in C89 with Objective-C for the Cocoa API calls, also built on NSSpeechSynthesizer, and needs nothing but the Xcode Command Line Tools to build.
A nice side effect is that nsspeaker compiles and runs on systems as far back as OS X 10.5 Leopard, unlike AVSpeech-based swiftmac, which needs macOS 10.14/10.15 at minimum due to Apple's own framework limitations.
I've tried to implement the full Emacspeak protocol and keep the server fast and responsive.
I'd appreciate it if some of you could give it a try:
https://github.com/Daniil-Gusev/nsspeaker
Building is just make.
With respect, Daniil