Link to issue number:

A partial fix for issue #13876.

Summary of the issue:

With eSpeak, when rate boost is off, the speech rate is slightly higher (7% according to espeak-ng/espeak-ng#131 (comment)) when rate is 99% than when rate is 100%.

Description of user facing changes

With eSpeak, a speech rate of 100% corresponds to the fastest speech rate without rate boost; no more rate drop between 99% and 100%

Description of development approach

_espeak.maxRate is the rate used when NVDA speech rate is 100%.
So set _espeak.maxRate to 449 instead of 450. Indeed according to espeak-ng/espeak-ng#131:

• the sonic library is used for eSpeak rate set to 450 or higher for many years (instead of 451 before).
• other ATs may already be using this new value, e.g. speech-dispatcher (cf. increase espeak speed to maximum without sonic brailcom/speechd#603)

This allows to have a continuous increasing of speech rate when rate boost is off and to reserve the use of the sonic library for rate boost on.

If one day, eSpeak turns back to 450 for maxRate (what seems unlikely), we may revert this PR's content to follow eSpeak's decision.

Testing strategy:

Read the following lines in American English:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19

Tested with rate from 0%, 10%, 20%, ..., 90%, 91%, ..., 99%, 100%
Checked continuous increasing of speed.

Known issues with pull request:

The 7% speech-rate drop is still present between 18% and 19% when rate boost is on. This has to be fixed on eSpeak's side.

Change log entries:

Bug fixes
When rate boost is off, eSpeak's rate does not drop anymore between rates 99% and 100%. (#13876)

Code Review Checklist:

• Pull Request description:
  • description is up to date
  • change log entries
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• API is compatible with existing add-ons.
• Documentation:
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English