Reception: Most monitors use the same digital technology (Dect) as cordless home-phones.

Range: Audio models all achieved roughly 40m, the video units about half that distance.

Thermometer: It detects air temperature near the device.

Alarms: Warning sound if reception is lost, the battery is low or if the temperature changes.

Pager/Parent find: Constant noise that helps to locate the handheld receiver.

Graphical sound-meter: Lights on the parent unit that indicate how much noise baby is making.

Intercom: Often known as talkback.

Nightlight: Many models now include it on the child-unit.

BEST FOR...  AUDIO QUALITYS 

BT Baby Monitor Pacifier
£90, shop.bt.com

BEST...  ALL ROUNDER 

Phil & Summer Infant Baby Touch
£180, summerinfant.co.uk

BEST FOR...  VALUE 

Tomy Digital TD300 Monitor
£59, tomy.co.uk

BEST FOR...  SHARING VIDEO 

Samsung SEW-3030
£150, samsunghomesecurity.co.uk

BEST FOR...  BATTERY LIFE 

Philips Avent SCD535 DECT
£100, philips.co.uk

BEST FOR...  NEW PARENTS 

Tommee Tippee Digital Sensor Pad Monitor
£100, tommeetippee.co.uk

BEST FOR...  INNOVATION 

AC1100 Digital Video, Movement & Sound Baby Monitor
£249.99, angelcareuk.co.uk