I don’t think they should be blocking each other, but OpenEars suspends listening during TTS so that the TTS speech doesn’t become part of the recognized speech. This shouldn’t be the case when using headphones since the isolation of the mic and audio output from each other means there isn’t the same danger of confused recognition. Is that the issue you’re seeing? If not, I guess I’d need a more detailed clarification of exactly what is happening versus what you’re aiming for.