How to set Piper speaking rate?

Configuration Voice Assistant
1

I’ve got Piper running as an internal Home Assistant add-on, and in companion with an external Whisper service, seems to function reasonably well for my satellite speaker.

The voice I’ve selected for Assist Text-to-speech is “alan (medium)”. Also good, though Alan enunciates a little slowly and carefully for our tastes.

I’ve tried to alter the Piper Add-on configuration settings to speed him up a little, changing from the default 1.0 setting to 0.75 (and now 0.65) and restarting Piper, but it doesn’t seem to have any effect.
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Is there a way to adjust the Piper ‘length scale’ value directly within Assist?
Or, any other suggestion to adjust speech rate?

Thanks.

2

Hmm. Perhaps the length setting only affects custom sentences. Some of those on our system do seem to be a little too fast now.
However, an “I’m sorry, I do not understand that” is still overly slow.

3

I believe you have to clear the cache (tts.clear_cache) after adjusting the rate, otherwise it will just play back the previously-generated recording.