Baby monitors may have 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. Other monitors have a vibrating alert on the receiver making it particularly useful for people with hearing difficulties.
The Infant Optics’s range within our test houses was never an issue, and, as with others we tested, we had to walk outside and down the street before losing the signal. The image quality was good enough to make out facial details 6 feet away in a completely dark room (as it was on others we tested). It’s easy to add more cameras to the set (you can use up to four Infant Optics add-on cameras, which are separate purchases, usually for about $100). You can mount the camera on a wall easily, pan and tilt 270 and 120 degrees respectively, and you can set the parent unit to scan between multiple cameras to keep an eye or ear on everybody at once—another nice feature that’s not unique to this model.
If all you want is a no-fuss audio monitor, the Bump and Baldwin both recommend VTech’s DM221 audio monitor, which consistently garners a lot of accolades. Using digital audio technology, the DM221 offers clear audio transmission and eliminates the crackle of analog models. A two-way intercom allows you to talk to your baby, while a five-level sound indicator can visually alert you to cries from the other room. The transmitter also features a soft night-light for your child. And don’t sleep on its compact size, which makes it perfect for travel.
Frequency: Some baby monitors operate on the same 2.4GHz frequency band as household products like microwaves, cordless phones, wireless speakers, and so on. When the monitor is on the same frequency as a number of other products, you can experience interference and static. You may want to get a monitor that uses a different frequency like 1.9GHz, which the Federal Communications Commission sets aside for audio-only applications. It's called DECT, or Digitally Enhanced Cordless Telecommunications.
We tested a Nest Camera for the sake of comparison, to see the advantages and disadvantages of a popular security camera versus baby monitors designed expressly for watching babies at home. We have also considered the Arlo Baby monitor, which we’ve seen in demos but not tested firsthand for this guide. Our findings are in Why not just use a security camera? For far more information on all the other similar options—including a detailed look at other Arlo indoor security options, like the Arlo Q—see our guide to the best wireless indoor home security camera.
The features we focused on were those we thought either increased the performance of the monitor or made it more user-friendly for parents and increased the odds of getting good quality sleep. We looked for monitors that have sound activation that keeps the parent unit quiet when the baby isn't crying, so parents can potentially fall asleep faster because they don't have to listen to white noise. Some of the monitors were so loud, even at low volumes, that the white noise might keep light sleeping parents awake; this defeats the purpose of having a video product to begin with. We also liked the models with screens that automatically "wake" and/or go to sleep.
For parents who want to monitor their baby’s cries from the office, or the gym, or Tahiti, the BB-8-looking iBaby M6S syncs right up to your house Wi-Fi connection ⏤ so instead of using a dedicated handheld receiver, you watch all the action on a smartphone app. It offers impressive 1080p HD video (with record function), a 360-degree view with 110-degree tilt, and an array of high-tech sensors including motion, sound, in-room temperature, air quality, and humidity. The only thing it seemingly won’t do is fix your X-Wing fighter. Although it makes up for it with night vision, two-way talk, and 10 programmed lullabies and bedtime stories, to which you can even add your own voice.
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.