The number of teens who voice call on their phones every day dropped 50% between 2009 and 2012. Just 3% of UK Millennials now use the function daily. With texts, iMessage and WhatsApp becoming the preferred method of communication, can audio message app Cord get us talking again?

Landline usage is in decline, but providers still have a significant market share; although younger people are turning away from landline voice services, users of all types still have fixed line connections. Is this set to continue?

"It's kind of awkward to leave voicemails now," says 22-year-old college graduate Chris Paul. His sentiments are echoed by his generation, with research showing that voicemail use dropped 8% between October 2013 and April 2014, as texting becomes the dominant communication method.

One in ten Americans are clinically depressed. As busyness becomes a status symbol for Millennials, the stress is mounting. 'Text therapy' platform Talkspace appeals to a generation accustomed to immediate answers with a tap of a smartphone – but is it effective?