In case you are tired of the low quality Google TTS voice commands, here I found the perfect alternative. Russian guys ported the amazing Ivona Voice (occupied by Amazon) to android.
Here a user from XDA put everything together:
Here is a link to all files you need:
Download your voice
Extract to: …/ivona
Download APK zip file, install APK (in my case only version c allow me to choose a directory)
Go to voice settings and choose Ivona, and apply the right directory. Ready.
Take a look into the manual, there’s is everything described clearly.
Edit: I’m on Android 10/LOS17, works perfectly