Week 1: Principles and Practices¶
This week I worked on defining my final project idea and started to getting accustomed to the Fab Academy infrastructure, git, mkdocs, and the documentation process.
Initial Conception of Final Project¶
The original concept came to me in late 2020 after the intersection of two events in my life.
- I became aware of a cool audio technology called bone conduction headphones.
- I visited the dentist for a routine checkup, but was unfortunately informed I would need cavities filled. This involved the normal suite of jaw-wrenching drill sounds and powertools operating on my teeth.
While intrigued, the idea was still not fully formed in my head. The first thing I did was procure my first pair of bone conduction headphones. The initial sensation is strange, almost itchy if you are the ticklish type. And the fidelity of this pair was just ok. I suspect they might be a knockoff of another brand. Even still, the technology was intriguing and seemingly not widely understood.
This pair quickly became my regular set of runners, having exhibited an important feature which most headphones cannot boast. That is the ability to still hear your surroundings and maintain situational awareness, since your ear canals are unblocked. To this end, the US military makes great use of the technology.
Even still, this struck me as a technology that is potentially underutilized and perhaps, may not have found its killer-app. And thats where my thoughts of the dentist came in. What if we could combine the technology, with noise cancelation technology, in order to cancel-out the uncomfortable drill-sounds vibrating through the patients teeth, jaw, and skull. So not only will the patient be able to listen to their own music in the dentists office, they will be able to do so without the high-pitch vibrations traveling through their skull and towards their inner-ear. And the sugar on top, is that they will still be able to hear the dental staff and maintain conversation.
This theory relies on some assumptions:
- A large portion of discomfort in the dentists office comes from sound waves traveling through the teeth/skull and towards the ear canal.
- It will be possible to “cancel” or invert these incoming signals
- The sound waves traveling through the air and towards the ear canal are not a huge cause of discomfort
- This will lead to a more pleasant dental experience.
The next time I went to the dentist, in mid 2021, I was sure to bring my pair of bone conduction headphones along to run a simple test. I am biased of course, because I want the idea to be a winner, but I maintain that the simple act of conducting my own music through my bones improved the pleasantness of my dental experience by atleast 10-20%. While not noise canceling, the added noise did seem to help “drown-out” some portion of the dental disturbances. It also seemed to do so better than external speakers or traditional headphones could.
Side note: I suspect traditional headphones and especially traditional noise canceling headphones would do more to hurt the problem than help it, as these technologies tend to make the user feel as if they are inside their own head. For instance, when wearing bose noise cancelation headphones, one can hear themselves chewing especially loudly. Because of the way bone conduction headphones seem to work, I suspect we will not have this problem.
Enter Fab Academy Final Project¶
Leading into Fab Academy, I decided that this would potentially make for a good final project. One reason for this, is because my background has not involved much electronics. This does not stop me from having electronic invention ideas, but it does make me scared to even begin such projects. Rarely will I have an opportunity to spend so much time dedicated to an electronics project, so I may as well try and build my best idea. Better yet, if I could end this course with a working prototype for this idea, that would be the sugar on top. IP and secrecy be damned. If you’re reading this, and you’d like to give it a go, please be my guest! I don’t suspect this will be easy.
With that in mind, I began to sketch an ideal final product for the Noise-Canceling Bone-Conducting Headset.
I am sketching on my new 2-in-1 laptop and using the Concepts app for Windows. In the spirit of learning new tools, this will be my first forray into digital sketching.
The ideal final prototype:
- senses interference detected in jaw/skull (red wave)
- cancels interference with destructive interference conducted into skull (green wave)
- is wireless/bluetooth connected
- accepts user music via bluetooth and conducts into user skull (yellow wave)
- is generalized to handle multiple different sources of interference
- is one size fits all because of
- an adjustable strap
- other degrees of freedom to flush against different cheek bones
- is comfortable and uses biocompatible materials
- utilizes custom electronics
Minimum Viable Product¶
Of course, there exists the possibility that this ideal prototype will prove out of my reach. I can think of two reasons this may happen, but I’m sure there are more. * Sensing and ‘canceling’ the interference in the skull is too difficult or not possible. * One of my assumptions above is incorrect.
With these risks and spiral development in mind, I will attempt to produce an MVP as soon as follows. I suspect this MVP will look something like this.
The ideal MVP:
- will be the simplest possible proof of concept
- will use a block of wood as a proxy for a skull
- or something more viscoealstic and accurate to human tissue if available
- include the beginnings of the core electronics that will go in the final prototype
- an additional input signal as a proxy for the user’s inner-ear
- will be connected to an external powersource
- will not include bluetooth/music
- will have some visualization of i/o to make iteration occur quickly
Ideally, this MVP can serve as a go/no-go test. I suspect should aim to have a working MVP by the end of the input devices week, April 27th. That way, I will still have time to pivot to a different project should this one be a no-go.
Sources¶
Note: All design files and images can be accessed in my git repository found here.
All works shared on this site 'A Fab Academy Journey with Charlie Horvath' by Charles W. Horvath are licensed under Attribution-NonCommercial-ShareAlike 4.0 International
