A man in France has been fined $300 for using the speakerphone on his mobile phone while in a train station.

The man, who has only been identified as “David,” told an interviewer from CNN affiliate BFMTV that the incident occurred while he was waiting for a train at Nantes station in the west of the country on Sunday.

He told the outlet that he was talking to his sister with his phone on speaker when an official from France’s state-owned rail company, SNCF, intervened.

“An SNCF security person told me that if I didn’t turn off my loudspeaker, I was going to be fined €150,” he told BFMTV.

The man said he initially thought it was a joke.

“I think the person was offended. She took out her notebook and fined me,” he added.

In the event, the fine turned out to be even higher – €200 (A$329) – because he did not pay it on the spot.

The passenger told BFMTV that he has hired a lawyer as he plans to contest the fine.

CNN has reached out to SNCF for comment.

Making calls or watching videos without headphones in public spaces is a modern habit that many find infuriating. When one Reddit user recently asked “What do you secretly judge people for?” the response “When they watch TikToks loud in a quiet room without headphones” was upvoted 13,000 times.

Debrett’s, Britain’s bible of all things etiquette, published a piece in 2023 on the new rules of cell phone use. It states: “Keep phone calls to yourself. If you’re making a video call in a public space (or if you’re just too lazy to hold the phone up to your ear) you must use headphones or earbuds.

“Nobody should be forced to listen to your phone conversation; it will be annoyingly distracting and might be intrusive or embarrassing. The person at the other end might object if they realise their conversation is audible to a train carriage full of unwilling eavesdroppers.”