HuffPost: HumanKind brings you an advent calendar of kindness, celebrating good deeds and the people doing them, in order to inspire and bring hope this festive season. Find out more about the series, and uncover new stories daily here. 

You’d expect it to be loud and bustling in the call centre of Samaritans’ Soho branch, but actually you could hear a pin drop.

Volunteers sit at desks, fenced off by noise-cancelling screens, speaking into their headsets with lowered yet empathetic voices. It’s reminiscent of a library – a soothing and quiet atmosphere, where there’s clearly important work to be done.

This particular branch has been operating on a 24/7 basis since 1987 – the lights haven’t been turned off since then and the front door has always been open to passers-by.

Over Christmas, dozens of volunteers come from across London to make sure the phones are answered so that no-one is left to feel alone – even in the middle of the night.

We spoke to three volunteers who will be taking a break from the turkey to offer their time (and ears) to people in crisis this Christmas.

HumanKind is HuffPost’s celebration of kindness, featuring people who do incredible things for others or the planet – transforming lives through small but significant acts. Get involved by joining us on Facebook. You can also nominate those who deserve to be shouted about by filling in this form or emailing natasha.hinde@huffpost.com.