Drop "For English Press…."

If the application is multi-lingual and you need a language selector, drop the “For English” option from the list of language options if the application starts off speaking in English. Have it pause 1.5 or 2.0 seconds after the language instructions have completed and then proceed with the rest of the dialog in English if the user does not respond.

System: Widget Solutions. [Audio Icon]. Intelligence at your service. Para Espanol, oprima el dos.

Establish that they can use speech

If the application is speech enabled, make sure that your opening prompt conveys that upfront. Have the first interaction ask them to answer a yes/no question, for instance, by explicitly saying, “you can say ‘yes’ or ‘no’”. However, make sure that you don’t explicitly announce to the user that the application is speech enabled. Chances are that, whatever formulation you choose to make that announcement, some people will not understand what it means.

Never ever say, “Please listen carefully as our options have changed”

An awful invention that must be banned once and for all. Make excluding this expression from you VUI design a non-negotiable principle for which you are willing to walk away if any project manager insists on having it included.