You can also use google "voice services". Its an option if you want.
Its a package you can get from play store {or aurora). I think installing it would require the presence of some google components such as GFS and " play services".
Once installed and language model downloaded, then you can block its internet access. I think that's how it works.
Further, the google play components can also be disabled after installation. However this can cause apps installed after the google component installation to see the components and use the google notification system, which wont work cause you have disabled the components. So certain apps needing notifications that rely on google components for delivery, wont receive them if you disable the components. Just fyi