My language settings are only set to English, but my iPhone speaks certain emoji (like 🙆♂️ and 💁♂️) in a Japanese accent when I select them in a message and tap Speak. Can anyone explain? Here's a visual example of what I see when I select mixed words and emoi:
It's possible you have a non-English language selected in Speech settings?
Choose a voice for Speak Screen and Speak Selection
Go to Settings > General > Accessibility > Speech. Enable Speak Selection or Speak Screen, or both. Select Voices. Choose the one voice and dialect you would like both Speak Screen and Speak Selection to use.