accessibilitySpeechPitch lets you emphasise something changing VoiceOver's pitch. The value goes from 0.0 to 2.0. The default is 1.0. Twitter could change pitch to read hashtags, for example, avoiding repetition but still signalling they're there.

Example shows how you can specify changing the pitch for a portion of an attributed accessibility label, using the accessibilitySpeechPitch attribute, for hashtags on a tweet. By default VoiceOver would read something like “Writing about developing accessible hashtag iOS apps in hashtag 365 days iOS Accessibility hashtag accessibility hashtag a 11 y”. There’s lots of repetition of the word hashtag. But it could be changed so it says “Writing about developing accessible iOS apps in 365 days iOS Accessibility accessibility a 11 y” where iOS, 365 days iOS accessibility, accessibility and a 11 y, is read with a lower pitch of 0.7.