Tuesday, September 27, 2011

Chanter: brainwaves, EEG, meditation and Flash

I've released a desktop app called Chanter. It's a tool for people who'd like to improve their meditation or mindfulness skills, which gives instant audio feedback about your state of meditation. In short, the app plays a mantra-like audio loop, and changes the pitch of the loop according to the meditation level of the user.

You need a NeuroSky headset, the MindWave or Mindset, to make this work. The headset registers brainwaves - EEG - that are sent to the computer wirelessly, using a dongle that comes with the headset, and a small software program that you need to install.

Seantheflexguy was the first developer who made me aware of this exciting hardware, and he also wrote an open source ActionScript 3.0 API, making it simple to hook up the headset to a Flash or AIR project. Actually I'm not using that API, as NeuroSky also provides some brief and clear instructions on making Flash listen for messages from the headset.

Brainwaves and level of meditation
The messages returned by the NeuroSky software are not only the delta, theta, alpha, beta and gamma bands of the EEG, but also two values that are based on these bands: concentration and meditation. Obviously, Chanter listens to the meditation value, although concentration and meditation are not opposites; the 'ideal' state of mind would be a value of 100 for both categories.

Why Chanter?
There are quite a few apps in the Neurosky store, most of them simple games, with an emphasis on mind exercise. The one that - in my opinion - stands out is another meditation tool called Dagaz. What struck me though is that all available apps are based on the idea of visual interaction, in other words: you need to look at your computer screen while experiencing the tool or playing the game. My next thought was: wouldn't it be nice to build a meditation tool that is based on audio only, so that you don't have to look at your screen when meditating, a tool that even allows you to close your eyes? This idea resulted in Chanter.

A promotional website can be found here, and the app is available in the NeuroSky webstore. Below are a couple of screenshots of the app.

Pitching the mantra loop

The code for changing the tone of the mantra mp3 that the user selects is derived from a class by (surprise, surprise) Andre Michelle. It's not real pitch shifting, which would mean maintaining the same tempo, but it suffices for the short loops that I'm using.


  1. Hi Jeff. I have a Mindwave headset and I agree with you. Sound feedback apps are missing considering that eye-closed meditation is an easier way to achieve these goals. I tried to buy your application "Chanter" at the Neurosky store page. As I live in Buenos Aires Argentina, I can´t find the way to be accepted by the electronic form, because Argentina is not included in the list of accepted countries. I am planning to develop a small randomized controlled trial using meditation techniques in Substance Use Disorder and I would like to try Chanter as a possible app to monitor training advances in those patients.
    Do you have an alternate page where to buy this application?
    Thanks in advance, and congratulations for your simple and useful idea.
    Best regards,
    Carlos Sagasta, MD

  2. Hi Carlos,
    thanks for your mesage, I will send you an e-mail soon :),

  3. Hi Jeff,
    I have the same problem, as I live in Hong Kong.
    Would you mind also send me the alternate page to buy the application?
    Best Regards,

  4. hi Eric,

    there is no alternate page, but I will forward your address to NeuroSky.


  5. Hi Jeff,

    I have a copy of your Chanter program. rather than using the built-in meditation profile, have you thought about putting specific brain wave ranges? ie. I'd like to be able to try and stay in a specific brainwave state ie. alpha/theta/etc. for x number of minutes.

  6. I never thought about that, but that would really be a tough training program :)

  7. Yah...If you were in alpha state, doubt you could remove all other states entirely (ie. when looking at one other program it shows a graph of all alpha/beta/etc and there's still some beta going on when I'm supposedly in a more alpha state)...I guess the idea would be to try stay focused on one particular major state..ie. alpha.

    Thinking something along the lines that this guy offers, but using the Neurosky Mindwave device...


  8. Dear Jeff,

    Thank you very much for the app. I use it regularly, sometimes with the audio, sometimes without — to compare the resulting graphs. It would be nice to have a regime without the audio but with a special sound at the end of session. Just to indicate that it's over. Anyway, you've done a great job, the app works flaulessly and helps a lot in my everyday life.

    Best Regards from Moscow and once again Thank you so much!


  9. Hi Elya,

    thanks for your message. What a nice idea to simply use it without audio, never though of that :)

  10. Hi,

    Do you have plans to port Chanter to the iPhone/iPad? I think it would make a great app.


  11. I don't have the headset for mobile yet, but it's a good idea, thanks.

  12. Dear Jeff, I am back with the same iPhone/iPad question. Please :-)

  13. As you write, the ideal state would be 'zone' with attention and meditation both at 100. I think it would be really useful with including an alternative session type in Chanter, with Zone as the goal, rather than just Meditation. Do you like the idea? Would it be hard to implement?

  14. hi Raven,

    thanks for the idea. It would be possible to implement this. However, at the moment I have no plans to build in new features,


  15. Jeff,
    Great App. I have a question for you. All the sounds in the app fade in and and out. Is there a way to get a continuous sound, so that there is never any silence in the app?


  16. Never mind. I figured out I could achieve this by clipping the MP3's in the sound directory. Thanks anyway.