Google TTS does not work: getAudioContent() is null

Add-ons Text-to-Speech
1

After VoiceRSS suddenly stopped working, I wanted to switch back to Google TTS. I had used Google TTS a few years again, so I still had my Google project with TTS enabled and in production. I just needed to create a new OAuth client .

So I did everything described in the binding doc and I get not errors doing that.

But when I want to output text, I get this error:

2025-06-29 14:49:37.543 [DEBUG] [.googletts.internal.GoogleTTSService] - Synthesize 'Test ' for voice 'googletts:deDEChirp3HDAchernar' in format AudioFormat [codec=MP3, container=NONE, bitDepth=16, bitRate=64000, frequency=44100, channels=1]
2025-06-29 14:49:37.594 [ERROR] [b.core.io.console.ConsoleInterpreter] - An error occurred while executing the console command.
java.lang.NullPointerException: Cannot invoke "String.getBytes(java.nio.charset.Charset)" because the return value of "org.openhab.voice.googletts.internal.dto.SynthesizeSpeechResponse.getAudioContent()" is null

I see in Google Console that there are a number of errors trying to use the API, but no details. And I found no way of looking into any logs on the Google side.

Tested with OH 4.3.3 and 4.3.5.

Any hints would be greatly appreciated. Thanks!

Edit:
Just realized that the voice types “Chirp” and “Chirp3” do not work, but “Standard” works!

2

I was testing with the new HD voices but it looks like they don’t work… Could it be Google side or is it the binding who doesn’t send the voice data correct to google? Just curious, because the new voice are a bit more natural i think. Although, Wavenet is also pretty good.

3

the new voices are awesome,no comparison with the old standard or the wavenet ones.I wish there is a way to use the new Chirp voices…