To use the good offline map app Here Wego, you need TTS. I downloaded it successfully via Aurora, but I can't add any language for offline use. This means that Here Wego generally doesn't work with voice, not even online.
I've read many posts, including in this forum, but none of them had a satisfactory solution. RHVoice, for example, has no German language available. Other apps are obviously very outdated and buggy. I downloaded an older version of Google TTS via APKpure, but it wouldn't install at all.
I read somewhere that it is absurd to "reinvent the wheel" when there is already a good solution - with Google. Unfortunately, this is not yet included by default in GrapheneOS.

In short: I need this function and would like a good solution with voices that I like to listen to when the navigation system accompanies me on the roads.

Does this solution exist?

PS: Apart from that, I am largely satisfied with GrapheneOS. The installation went well. And the issue of voice quality when making calls still needs to be addressed. An esim-card delivers choppy, hard-to-understand speech to the other person.

Update:
Now there is progress with Google TTS. Now it happened that the German language could be downloaded as offline available language.
That was for Speech input settings. Google TTS is defined for Speech input.
But the navigation app Here Wego needs a setting for speech output. Now I found out that I have to click on Google TTS to start it. The GUI didn't show it with some kind of highlight or checkboxes.
Voices in Here Wego are active now.
Solved.

a month later

Did you grant the Speech Recognition & Synthesis App network access? I am still not able to download the german language for TTS only for STT and if I disable the network access for the App the speech output of HereWeGo stops working.

    linuxgoblin Yes I did grant network access after recognizing that it is needed to get voice in my new locusmap app too.
    To install a language, this is not done directly from the app, but via >Voice output >Preferred module >Click on the gear wheel >Install language data >Select language >Select voice.
    There is no button for saving. The selected voice is downloaded and is available.

    • harp replied to this.
        9 months later

        Dan-cer But are you able to use the downloaded voice offline, without network-permission granted to Speech Recognition & Synthesis App? When I try to download a voice (with network permission granted), e.g. German, it shows "Downloading..." but this never stops. And tracking network-traffic shows there is nothing downloading, no traffic.

        With network-permission granted to Speech Recognition & Synthesis App and beeing online I can use every Voice for TTS in any app. But without permission no voice except English works. So I'm still unable to download any voice, English-offline-voice must have been included while installing the app. But every other voice seems to be used in the cloud.