A group of campaigners set themselves a task of measuring how noisy each journey was on the London Underground.

They found noise levels on some Tube routes reached 100 decibels - which the audiologists say is harmful to commuters' hearing.

Transport for London (TfL) is being encouraged to put up warning signs in parts of the Underground network where noise levels are high.

However, TfL says Health and Safety Executive guidance suggests Tube noise is highly unlikely to cause long-term hearing damage.