To activate ChatGPT's voice chat feature, first click on the headset icon on the right side of the ChatGPT chat box. Then click the "Next" button below the "Voice Conversation" pop-up message to view five different voice samples. Then select any voice and tap on the "Confirm" button at the bottom.

ChatGPT's voice chat feature will now be activated on mobile phones if you allow the use of various devices including smartphone microphones. To disable the voice chat feature, click the cross button.