Hi @KeithWood1,
Welcome to Google Cloud Community!
Google Cloud offers $300 in free credits for new customers to try out Text-to-Speech and other Google Cloud products. This credit can be used over the first 90 days. However, once you exceed the free credit limit, charges may apply.
Additionally, you may refer to this link to see the pricing table which shows a tiered pricing system where users get a certain number of free characters depending on the chosen voice, after which usage is charged at a per-character rate that varies based on voice quality and features.
It also mentioned there that:
Text-to-Speech is priced based on the number of characters sent to the service to be synthesized into audio each month. You must enable billing to use Text-to-Speech, and will be automatically charged if your usage exceeds the number of free characters allowed per month.> > If you use other Google Cloud resources in tandem with the Text-to-Speech, such as Google App Engine instances, then you will also be billed for the use of those services. See Google Cloud’s pricing calculator to determine other costs based on current rates.
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