Baby monitor

Audio baby monitor

A typical baby monitor, also known as a baby alarm, is a simplex (uni-directional) transmitter and receiver system used to remotely listen for noises made by an infant. The transmitter, equipped with a microphone, is placed near to the child and the receiver equipped with a speaker, is carried by, or near to, the person caring for them at the time. Some baby monitors are duplex (bi-directional), using transceivers that allow the caregiver to communicate back to the baby (parent talk-back), and some have a feature allowing music to be played on the transmitter (and thus played to the child).

One of the primary uses of baby monitors is when the infant is asleep in a separate room or floor, allowing caregivers or parents to keep track of any problems while away from the baby.

Video baby monitors: baby cams

Some modern baby monitors also incorporate a digital camera to show video footage on the receiver in a similar method to web cams, and some others allow the receiver to be plugged into a television or to be included in a portable LCD screen (with batteries); they are called baby cams.

Some baby cams can work with low minimum light level (night mode).

Wired and wireless

Baby monitor generally uses wireless systems, but can also use corded ones (i.e. cable or X10).

Audio wireless systems, using DECT, are completely interference free and have a range up to 300 m

Video wireless systems:

1. Suffer from interferences with WiFi ( 2.4GHz) or TV signals.
2. Have shorter range than audio or X10 monitors.

A mix system offers a cord connection, using the home grid, and a wireless one from the outlet to the receiver.

Other features and technologies

• Baby monitors may incorporate a visible signal as well as repeating the sound. This is often in the form of a set of lights to indicate the noise level, allowing the device to be used when it is inappropriate or impractical for the receiver to play the sound.

• Some devices also incorporate movement sensors on the transmitter allowing it to warn caregivers of possible sudden infant death syndrome. Other monitors have a vibrating alert on the receiver making it particularly useful for people with hearing difficulties.

• It is common for the receiver to be small and portable and to use batteries as their source of power allowing it to go with the caregiver, around the house. The transmitter stays with the infant crib and is usually plugged into a socket. Some baby monitor packages include two receivers.

• Some monitors include dial-up and internet connection.

• The frequency used by the wireless audio devices usually lies in the range of 49–50 megahertz, though some models can go as high as 5.8Ghz. As with all wireless transmission systems there is the possibility that a receiver used by a third party could pick up the transmissions. To aid this many models allow a choice of bands. DECT advoid this problems.

• There have in the past been baby monitors that used a length of cable (around 100 m) instead of wireless sistems.

See also

• Bassinet
• Belt clip
• Lullaby
• Nanny cam
• Neck cord

References

• Baby monitors - information for deaf and hard of hearing people (factsheet)
• Baby monitors - information for deaf and hard of hearing people at the RNID, retrieved 14 January, 2005
• UK supplier of baby monitors