Claire Reilly/CNET

As a new mother, nobody tells you that you'll spend hours of your life sitting on the sofa with a noisy suction monster. No, not your baby -- your breast pump.

The Willow wearable breast pump is bringing a much-needed technological twist to one of the last bugbears of parenting, making it easy to express breast milk while keeping your hands free.

A plastic teardrop-shaped device that looks more like a Bluetooth speaker, the Willow sits inside the mother's nursing bra, detecting when she starts to express and adjusting the pump mode accordingly.

The milk is pumped into a nifty doughnut-shaped bag inside the unit, and a one-way valve keeps it in without leaking. According to Willow CEO Naomi Kellman, you can toss the bag around "and you won't lose any of that liquid gold."

At first glance, Willow has clear benefits over a conventional breast pump:

Cordless design slips inside a nursing bra

Simple buttons for suction level and operation

Pumps milk into sealed single-use bags

Senses when milk starts and when mother starts to express

Pairs with app for details on pumping time and volumes

But undoubtedly the best part of the Willow is the noise, or, more accurately, the silence.

I'm used to friends and family sitting in the living room with a breast pump that sounds more like the tanks in an industrial water treatment plant. But I held the Willow to my ear like a gloriously empowering conch shell and I could barely hear a thing. Nothing but the distant sound of relieved mothers.

That's the key selling point here. According to Kellman, this wearable breast pump is about giving mothers a bit of freedom.

"We knew we couldn't just reinvent the breast pump, we had to reimagine it," Kellman told me. "Women want mobility and they want their hands back... The Willow cuts the cords and gets rid of dangling bottles for good."

The Willow is due to launch in the spring, with the company set to sell a double pump set on its website for $429 (AU$590 or £350 converted) with milk bags going for 50 cents each.

Check out all CNET's CES coverage here.