Rio Olympics' oldest sound was forged in Swiss mountains

The mixture of copper and tin is melting in the Blondeau foundry during the preparation of the Rio 2016 bronze bells in La Chaux-de-Fonds, Switzerland January 21, 2016. REUTERS/Denis Balibouse

LA CHAUX-DE-FONDS, Switzerland (Reuters) - At this year's Summer Olympics in Rio de Janeiro, no matter how elaborate the opening ceremony or how sophisticated the live broadcasts, the final lap of athletics races will be announced the traditional way -- by ringing an old-fashioned bell.

The ritual, which lets athletes and spectators know the race is reaching its climax, has been a feature of the modern Olympic Games since they were first held in 1896. But it is also connected to a technological development.