Phones ring, elevators ding, light switches click, access control systems beep, and alarms blare out. Sound is a very present but little considered form of human-machine interface within our evolving smart buildings. However, recent technological innovations and creative new approaches take us beyond dings and beeps, potentially making "sound" a fresh interface market for smart commercial real estate (CRE).

We primarily interact with our buildings on visual and tactile levels, through buttons, touch-screens, and smartphones. The latest advances in video analytics and occupancy tracking mean we also interact with machines, albeit passively, as we move around a facility. "Smart sound" is developing in the home where voice assistants are gaining some traction. However, it still lags behind in CRE, where ambient noise and privacy are more significant concerns.

Having every device talking and beeping in the IoT-rich future workplace is likely to have the opposite effect on health and productivity than was intended. Each employee talking to a range of devices is equally undesirable on the grounds of noise-level and privacy in an office environment. Headphones offer many workers a break from office noise and a chance to listen to productivity-enhancing music or natural soundscapes but block all interaction limiting collaboration.

Sentien a startup in the Czech Republic is releasing a hearable smart headset designed to be worn all day. The Sentien Audio device is designed to be worn comfortably while leaving the ear open. This allows the user to listen to what is coming through the speakers while hearing what is going on in the world around them. Obvious applications include information provision for drivers, cyclists, and industrial settings where blocking sound could lead to accidents. Why not for noisy offices where sound-blocking can lead to collaboration crashes?

Sentien Audio resemble regular hook-over-the-ear headphones. The device conducts sound to the inner ear via bone conduction technology, which is now well-known. This leaves the ear open for real-world sounds, such as safety announcements, spontaneous conversations with colleagues, while also providing a sound-interface for listening to music, making phone calls, or interaction with machines.

Indoor wayfinding has become a prominent smart technology application, where wayfinders follow maps and guidance on their smartphones. When using all-day hearables, guidance can be given by voice, saving time and hassle of handheld devices. In the event of an emergency, building security would be able to send out mass messages or talk directly to specific people/groups.

This is particularly useful when raising the alarm is not desired, such as to avoid panic. Marketing would no doubt find numerous applications for the technology. Consider custom promotions highlighted to specific customers as they move around the store - akin to the advertising scene in futuristic sci-fi Minority Report.

Hearables could be the ultimate platform for digital assistants. Where digital assistants commonly exist, such as in the kitchens of smart homes, people are starting to get used to turning to their smart speaker whenever then have a query or command. Outside of these spaces, we suffer a beneficial but uncomfortable relationship with our phones, reluctantly opening them knowing the answer is just a few clicks away. With hearables, we take the convenience of that smart kitchen with us, while maintaining privacy.

"I noticed myself using the AI assistant much more than before," Sentien co-founder Imrich Valach told Voicebot.ai in an interview. "It's not distracting me, and it keeps me aware more than using my phone or looking [through smartglasses]. It can also play music. Real audiophiles might not like the quality, but it sounds fine for most people."

Hearables are just wearables for your ears. As such, they should be compared with other wearables, and for this level of interaction with the user, the competition is smartglasses. Like smartglasses, hearable devices offer a kind of augmented reality by inserting virtual elements into a real-world experience. Smartglasses do offer many advantages over headphones by working in the visual spectrum but are not as all-day friendly according to Sentien.

“I don’t think smart glasses are built for all-day use. They can be tiring. That’s why we are focusing on audio. We’ve mostly been testing materials and positions. We want to make sure there’s no rubbing or discomfort at all. It needs to be so comfortable for the whole day.” said Valach. “You can wear [Sentien] all day and not notice it when not using it, and they are not as expensive as smartglasses or a smartwatch,” he added.

Sound as an interface may not be considered "untapped" due to the efforts of smart speakers and the voice control market. However, through a combination of ambient noise, privacy, and the need to hear, sound as a human-machine interface has been limited in CRE. Future generations of hearable technology may find its way on to many ears to achieve what wearables always promised - to bring humans into the network.

"Audio is the first step. Then come the other senses," Valach said, triggering imaginative theories about a future Internet of Senses. At least for some of us.