The VTech DM221 audio monitor is the best choice in the category—it's consistently a best seller at multiple retailers, with thousands of positive customer reviews. Losing video is a major sacrifice, of course, but we could see this monitor being a good choice for parents of toddlers who are considering replacing a failing monitor, or people who want a monitor only so they can hear their kid crying out from a distant bedroom.
Features: 3.5" LCD Color Display: it shows real-time activity of your baby, is convenient for you watch your baby anytime. Two-way Talkback and Lullabies: this baby monitor built-in lullaby and support two way audio talk, convenient to comfort your baby and help baby fall asleep. Auto Infrared Night Vision: providing clear video even in dark room, so you can keep an eye your baby all day and night. Temperature Monitoring: this feature is very convenient for you to check the temperature of your baby room.(temp error is about /- 0.5℃) Long Effective Distance: with 2.4GHz wireless technology, can be connected in 100m with no interference..
One minor but potentially annoying flaw: The “on” lights on the parent unit are a touch bright, and you may be more sensitive to them since you’re likely to have the unit within view as you sleep. They appear as greenish yellow light from the face of the unit, and a charging light, which is blue when it’s fully charged. Depending on how sensitive you are to light, you may want to lay the display face down on a nightstand or cover the status lights with tape.
Wireless encryption: This ensures that no one else can tap into your monitor’s “feed” and see what’s going on in your house. WiFi-enabled monitors are great for portability and range, but may be more susceptible to hacking. If you go this route, be sure to secure your home wireless network and keep the monitor’s firmware updated. Otherwise look for digital monitors with a 2.4 GHz FHSS wireless transmission.