Following up from the Architecture Overview post, this post goes into more detail on how our Audio Meters securely recognise music whilst respecting the privacy of the venues we're installed in. Given the Audio Meter has microphones front and centre of its design, it's a question we often get asked far too often!

Privacy

Hopefully you are familiar with smart speakers such as Amazon Echo, Google Home and the associated technologies built into televisions where you can ask that your lights to be turned on or favourite playlist played. With the convenience of these devices came privacy concerns once people realised that the microphones are always listening for voice commands. The speakers typically have a small amount of processing on the speaker that detects the "wake words" (i.e. "Hey Google...", or "Alexa..."), but once those words are detected, the recorded audio is typically sent to the vendor's cloud to determine what action to take. As smart speakers are interested in what has been spoken so they can take the appropriate action, they actively work to remove echos, music and other background noise to isolate voice frequencies.

Our Audio Meters, on the other hand, operate in the opposite way to smart speakers. They are not interested in conversations – in fact, conversations can actually get in the way of music recognition! We've designed the Audio Meter with privacy at its core and as part of that, it actively works to remove conversational noise (e.g. think loud talking or singing in a busy bar or restaurant) to get to the underlying music.

The Audio Meter also does not continuously use the microphones – instead, we take a short sample every few seconds for music identification. A further key difference is that no audio is sent to our cloud - we do all the audio processing on the Audio Meter. We then run machine learning models on the sound to reduce noise and isolate the music before we perform the final step of creating an acoustic fingerprint. The fingerprint is a short representation of the acoustic characteristics within the audio that is sent securely to our cloud for recognition. In summary, we have no way of hearing what is happening in the venues where we are installed.

Security

One key principle of security is to operate "defence in depth" - this essentially means having multiple layers of security to prevent, detect and respond to threats. Our Audio Meters and cloud platform were designed and built with industry-leading security standards in mind. We've implemented robust development processes and ongoing measures to ensure their integrity, and we continue to regularly review and strengthen these systems.

Here are some of the practical outcomes for our Audio Meters:

• The Audio Meters are locked down so they cannot be connected to by an attacker to allow them access to the memory storing the audio - either on a local network or through a cable.
• They only connect to our cloud platform and use industry-standard secure communications to prevent man-in-the-middle attacks or other spoofing.
• The software on Audio Meters is securely controlled by Audoo and locked with private keys that are stored on the Audio Meter in our factory, so rogue software can never be accepted and installed during over the air upgrades or through direct access.

In our cloud platform, we get many security advantages from hosting with Amazon Web Services (AWS) such as physical data centre security, ISO27001 certification for key infrastructure and many services to develop with. Without getting too technical about it, here are the key features we use in our cloud platform to ensure security of the data we gather:

• Audit logging providing compliance and risk auditing
• Identity and access control – lock down access to defined user accounts and roles
• Secure networking and firewalls locking down network traffic and logging access
• Data segregation and end-user roles ensuring access to data is restricted
• Data Encryption – all data is transmitted over encrypted connections and all data stored is encrypted on disk

We made a short video that shows our approach to privacy and security:

I hope this post helped explain how our Audio Meters operate while respecting the privacy of venues we're installed in.

If you have questions, please get in touch...

Cheers,

Steve