How Your Ambient Noise Solves Proximity Pairing

Discovering the Perfect Solution


It began with a problem that we stumbled upon while developing a social networking application.

Interaction between nearby devices

People do a vast amount of things in close proximity. They exchange files, use social networks to befriend a new acquaintance, join online games, transfer money, etc. Such interactions would be much more efficient and prevalent if it was technologically possible to seamlessly connect devices without worrying about overhead.

Facebook Friending vs. Exchanging contacts with Resonance Nearby in Drop
  1. Be cross-platform. It should support iOS and Android at least, and ideally function in the browser Web App too.
  2. Accurately find devices that are actually nearby.
  3. Be fast. Detection time should be less than 10 seconds.
  4. Be simple, non-invasive and intuitive.

The Resonance Nearby Technology

We live surrounded by ambient noise. Voices, music, engines, footsteps, etc.

There is not a single place in the world that has the same ambient noise that you have right now, reading this article.

Using the parity of ambient noise and time we can conclude pretty surely that the devices are nearby. This caveat became the basis of our technological solution.

Resonance Nearby Architecture
Example of comparative analysis of fingerprints
Resonance Nearby in Action in the app Drop

Other solutions….


This is the most obvious way to meet the challenge of detecting nearby devices. The moment a user activates the GPS-supported “Nearby” function, we can obtain his current location and use server data to search for the nearest devices.

Accuracy measurement of Geolocation


An original approach to enhancing the precision of geolocation was proposed by a Californian startup, Bump Technologies, some eight years ago. Users were required to physically bump their smartphones together so the accelerometer captured the exact time of contact and sent it to the server, along with the location data. The algorithm would only pair devices with identical time of contact. This simple idea significantly reduced the probability of false positive results, and helped to significantly increase the search radius. Details of Bump’s functionality are described in this patent

Bluetooth and Wi-Fi

Due to restrictions imposed by Apple iOS and Android, devices cannot natively connect via Bluetooth. Only a certified Made For iPhone (MFi) Bluetooth module can be utilized by the apps. Exchanging data between these platforms is a challenging exercise that requires third-party solutions and work-arounds.

Audio Generation

Every mobile phone is equipped with a microphone and a speaker. You can encode an ID into a sound and play it on one device, while capturing and decoding it on another device within hearing range, and thus link the devices into a group. signal spectrogram sample


Comparative analysis, Resonance Nearby.