The company says the voices in ChatGPT were from paid voice actors. A final five were selected from an initial pool of 400 and it's purely a coincidence the unnamed actress behind the Sky voice has a similar tone to Johansson.

In "Her," Scarlett Johansson voices an advanced AI operating system named Samantha, who develops a romantic relationship with a lonely writer played by Joaquin Phoenix. With its ability to emotional responses, the parallels from GPT-4o were obvious.

Voice is about to become more prominent for OpenAI as it begins to roll out a new GPT-4o model into ChatGPT. With it will come an entirely new conversational interface where users can talk in real-time to a natural-sounding and emotion-mimicking AI.

Unlike other multimodal models, it will allow for real-time conversations and even an emotional and adaptable voice.