Drs Rutherford and Fry tackle a vexing case sent in by Daniel Sarano from New Jersey, who asks why people shout on their mobile phones in public.

Our science sleuths find the answer by delving into the inner workings of telephony with a tale of engineering rivalry, Victorian etiquette and early otolaryngology.

Featuring acoustic technologist Nick Zakarov and historian Greg Jenner, author of 'A Million Years in a Day: A Curious History of Daily Life.'

If you have any scientific cases for the team to investigate please email: curiouscases@bbc.co.uk

Presenters: Hannah Fry & Adam Rutherford
Producer: Michelle Martin.