Accessibility for blind people using VoiceOver

I’m sharing here some useful info on the topic of plugin’s accessibility for blind audio engineers:

Avid has made Pro Tools accessible to blind users on macOS using Apple’s VoiceOver interface.

They also made it relatively easy for users to control their plugins via their automation parameters as long as they follow these steps:

  • Make the plugin controllable via its automation parameters (also useful for everyone who uses control surfaces)
  • IMPORTANT: Make sure that the parameter’s “number of steps” is not too large (for example here at SR picked 1024 steps), because with Pro Tools’s VoiceOver keyboard control interface the parameter value is modified step-by-step, so having billions of steps is unusable. Note that this is especially important, and preferably addressed before a plugin is even released, because once you change this, the saved automations in pro-tools (and possibly other hosts?) from before the change lose compatibility with your updated plugin, requiring you to either make some compatibility-mode hack for your plugin or to lose the users’ saved automations :confused:
  • Make the parameters value-as-text display reasonable. For example “12.3 dB” is probably good while “12.2945323 dB” isn’t useful and reading all that wastes the user’s time and attention.
  • Make the plugin handle presets via pro-tools by installing the presets as Pro Tools librarian preset files. This way the user can switch presets from Pro Tools’s accessible and uniform interface. We install .tfx presets (from the RTAS days) to /Library/Application Support/Digidesign/Plug-In Settings/$PLUGIN/Factory Presets and those still work for AAX in new versions of PT afaik.
  • Test your plugins in Pro Tools with VoiceOver! Listen to how it reads each parameter name to make sure that they are not confusing. For example if you abbreviate “channel 1” to “ch. 1” then VoiceOver will read it as “Chapter One” so it would be better to abbreviate to “chan 1”. VoiceOver can be enabled in the System Preferences in the “Accessibility” section. See guides elsewhere for it’s keyboard shortcuts - it’s not hard!

It could be that I forgot some details because it’s been a while since I’ve dealt with this stuff. I’ve emailed this stuff with other devs before but thought that it would also be useful to post this here as a useful reference. Cheers! Yair