Making and taking calls by putting your finger in your ear sounds like the stuff of a spy movie but it could soon be a reality.

South Korean startup Innomdle Lab is developing the Sgnl watch strap that communicates with your smartphone via Bluetooth and transmits the sound of a voice caller — via the device’s "body conduction unit" — through your fingertip. By sticking your finger in your ear, you amplify the sound so you can hear, while a built-in microphone allows you to respond. The Sgnl app lets you choose what notifications you want to receive such as messages, email and calendar events and it can even track your health. Saemi Kim, member of Innomdle Lab, explains why this device has its finger on the tech pulse.

How did the Sgnl project come about?

It all started with a small idea. According to CEO Hyunchul Choi, "a colleague was boasting about his smartwatch, but was embarrassed by the fact that everyone around him could hear the conversation. As the number of smartwatch users increases, they will all face the same problem." From there, Choi began to wonder if there was a way to solve this and came up with the idea of using one's finger to transmit sound. He immediately proposed the idea to Samsung's internal corporate venture department and thus Sgnl was born.

How does Sgnl allow a user to make phone calls with their fingertip?

Sgnl is connected to a user’s smartphone via Bluetooth. When the user receives an incoming call, Sgnl will alert them through an LED snow fall display and through light vibration. Also, users can make calls to five contacts by scrolling through their contacts using the volume button and pressing the function button to make the call. 

When a voice signal is received from a mobile phone, Sgnl will generate vibration through its Body Conduction Unit (BCU) which transmits the vibration through a user’s hand to their fingertip. When a user covers their ear with that fingertip, the vibration is amplified inside their ear.

Tell us more about the Body Conduction Unit.

Sgnl’s key technology lies in its patented Body Conduction Unit (BCU), which is capable of transmitting vibrations through the body, which then can be converted to sound. Sgnl communicates with the user’s phone through Bluetooth, and when a voice signal is received, Sgnl will generate vibrations through its BCU. These vibrations will be sent through the user’s hand to their fingertip. When a user places their fingertip to their ear, the vibration echoes to create amplified sound within the closed space of their ear and they can speak through the microphone embedded in the Sgnl strap.

Isn't it weird to answer the phone with your finger?

With Sgnl, users can leave their phone alone. They don’t have to carry extra devices, such as a Bluetooth earphone. Also, users can hear voices more clearly even in loud places since the finger not only transmits the signal, but blocks out background noise. And there’s no need to worry about others listening in because only the user can hear what’s being said. Plus, placing a finger on your ear is just like holding a smartphone.

What features does the Sgnl app offer?

The Sgnl strap pairs seamlessly with the Sgnl app to make a person’s day healthier, more manageable, and organized. Sgnl app has the following features.

1. Call Reminder monitors your call frequency to significant others and offers discreet nudges.

2. Activity Tracking monitors a user’s health and tracks their daily activity. Users can get detailed information about their workout patterns and track their steps with the built-in pedometer.

3. Smart Alert. Users can keep their life on track and never miss an important alert. Sgnl will gently vibrate to alert them of any calls, texts or app notifications utilizing different patterns.

Is Sgnl safe to use?

Sgnl transmits a user's call through vibrations. It does not emit ultrasonic nor electromagnetic waves and so we promise that it is safe.

-Daniel Casillas