They say that necessity is the mother of invention, and it seems that's true of the global pandemic, which has seen not one, but two contactless doorbells being announced at CES, from Alarm.com and ex-Netgear subsidiary Arlo. The Alarm.com Touchless Video Doorbell works using a doormat sensor which rings when the caller steps on it. The Arlo Touchless Video Doorbell uses a proximity sensor which chimes and blinks an LED when it sees a person approaching.

The Alarm.com solution which it touts as a 'world first' boasts a 150-degree vertical field of view, which means you can see a full-length image of whoever is at the door, with an optimised app-view in portrait mode. The camera itself is full-HD with HDR and night vision. There's even a heater to stop it seizing up at low temperatures. The Alarm.com Touchless Video Doorbell integrates with other products in the range and offers a logic engine to trigger actions along with the doorbell - for example, turning on security lights when motion is detected.

Arlo's Touchless Video Doorbell, which has been listed in this year's CES honorees, boasts a 'privacy shield', essentially allowing the camera's surveillance and doorbell functionality to run independently if required. That means, if the doorbell is disarmed, it will only start recording video and audio if the owner opens the Arlo app. Arlo is no newcomer to smart doorbells, having launched several video and audio models over the past few years. The full details of this one are yet to be released, but Arlo's existing products tend to be at the premium end in both specs and pricing, with extras such as package detection already live.

Arlo Contactless Video Doorbell

Both doorbells are set for release later this year and are a response to the growing risk to key workers from Coronavirus spread by contaminated surfaces. That said, however, there's a slight problem in that, like many smart home concepts, they actually require a complete change in behaviour from that engrained since the first doorbells were manufactured in the early 1800s. In Alarm.com's demonstrations, they use a doormat embossed with instructions, which may not be to everyone's taste, whilst the Arlo model has the potential for false-positives, making it potentially unsuitable for doors with line-of-sight of the road outside.

Given that these are premium devices but are primarily designed to protect those calling, not the homeowner, installing them will be something of an act of benevolence that could prove a luxury in these post-COVID recession times. But we're really looking forward to seeing them close up as they have loads of potential.