THE ORIGINS OF NEUDIO
By Andy Jackson
18th May 2024
The idea for Neudio originated during the COVID pandemic. Needing a lock-down hobby, I had taken up the guitar again and nearly bought that Vox AC30 tube amp I’d always wanted as a kid. But I live in a terraced house and would like to stay friends with the neighbours, so instead I just bought some headphones and an audio interface to plug into.
The interface came with a free version of Ableton Live, which is amazing software for experimenting with sound. Soon I was trying to make music out of anything I could find, including all the recordings of brain signals that I was supposed to be analysing for work. The recordings had come from scientific research I was involved with on brain stimulation, where electrical current is sent into the brain to treat neurological conditions like Parkinson’s Disease and epilepsy.
At the moment, most brain stimulation is delivered in predetermined ‘open-loop’ patterns, which is a bit like trying to regulate the temperature of your house by turning your radiators on and off at set times of the day. This works, but not as well as a ‘closed-loop’ thermostat that responds to a thermometer in the room. Our research was trying to argue that ‘closed-loop’ brain stimulation, that responds to the real-time state of the brain, might similarly be a better way to regulate its functions.
I’ve always thought of music as humanity’s oldest and most sophisticated form of brain stimulation. Compared to the rudimentary effects of zapping the brain with electricity, music can elicit an incredible range of powerful physiological and emotional responses just by sending sound through the ears. But, extending the analogy, listening to recorded music is a bit like ‘open-loop’ brain stimulation, because that sound is delivered in a predetermined pattern (albeit often by amazingly talented artists). What if the music you listened to responded to the real-time state of your brain, more like the thermostat? So the music would influence your brain and, at the same time, your brain would influence the music.
I wasn’t quite sure what would happen, but it seemed like an interesting experiment to try. So when I got back in the lab, I took the equipment we had been using for ‘closed-loop’ brain stimulation and connected it through my audio interface to make music in real-time. We read the state of the listener’s brain using electroencephalography (EEG) sensors placed over the skin. These pick-up electrical brainwaves which turn out to have similar frequencies to rhythms in music. You can think of brainwaves as being like little swings that the musical rhythm is pushing on. Neudio works by setting up feedback resonances between these brainwaves and music, so as to either enhance or dampen their swing. Incidentally, my son was also born during lockdown, so I was getting a lot of practice pushing on swings around this time.
After a bit of trial-and-error, the experiment worked and we showed that it was possible to change brainwave activity using brain-responsive music, with a precision that I hadn’t expected. That’s exciting because there are lots of applications for this, which we can discuss in future. But for me the most interesting result came when we replayed recordings of brain-responsive music to our listeners a second time. Even though the music was identical, it no longer had the same effect because now it was just a conventional piece of recorded music. This showed that the brain really does respond differently when it is placed ‘in the loop’ with music, which is something that can’t be achieved by any recording on vinyl, tape or MP3. So if I wanted to share brain-responsive music with anyone else, I was going to have to find a way of taking the technology out of the lab…
