I think most settings tend to come from the style guide set by whoever you are working for, and I'm not sure if these are language dependent.  For example, Netflix use this:

I.14. Reading Speed

• Adult programs: 20 characters per second
• Children’s programs: 17 characters per second

But I did subsequently find this for German language:

16. Reading Speed

• Adult programs: 17 characters per second
• Children’s programs: 13 characters per second

Interesting... I didn't expect to see a difference at all.  Certainly there would be a difference in speed for me as a poor German speaker, but I expected it to be the same for native speakers.

Maybe worth checking the style guides for others and see if they have similar guidance that would be of help.

I think most settings tend to come from the style guide set by whoever you are working for, and I'm not sure if these are language dependent.  For example, Netflix use this:

I.14. Reading Speed

• Adult programs: 20 characters per second
• Children’s programs: 17 characters per second

But I did subsequently find this for German language:

16. Reading Speed

• Adult programs: 17 characters per second
• Children’s programs: 13 characters per second

Interesting... I didn't expect to see a difference at all.  Certainly there would be a difference in speed for me as a poor German speaker, but I expected it to be the same for native speakers.

Maybe worth checking the style guides for others and see if they have similar guidance that would be of help.

Paul

Thanks a lot for your research! I don't do a lot of subtitling, it just comes up occasionally. What I find is that characters like commas or full-stops have a lot to do with how much time it takes to speak a line properly. I wonder whether a length estimate could be queried from a TTS service? Does Microsoft return the length of a spoken text? I know that would add some complexity, but it would be helpful if one is willing to spend the money (or the free budget) on it. I would.

Daniel