it’s probable that many of you already know about and understand the idea of active noise canceling headphones, (ANC). They’ve been around for a while. The idea is that beyond natural noise cancellation, more accurately called noise isolation, you get from closed back headphones. Headphone models that offer active noise cancellation have microphones on the outside that do some acoustic magic.
You may have experienced where when listening to a radio to a station whose signal isn’t coming in the best either becomes stronger or weaker when you move in respect to the radio, or move the radio in respect to its environment. This is an example of constructive and/or destructive interference. Going deeper in explaining this is very doable, it’s also all math, it’s also how noise canceling headphones work.
Microphones on the outside of your headphones, probably closed back, take in the sounds of your environment, create an opposite wave form to those sounds, and then feed them into your headphones. They aren’t perfect, but many are very good, which I have realized over time is in this case good enough. If noise canceling headphones can reduce sounds by say more than 50-60DB, even the loudest sounds are more bearable.
Then, years later it seems, a clever person working at a headphone company thought, hey we could also take the sounds taken in by those microphones and make a mode where listeners can actually hear what’s going on around them. This is transparency mode. Also some times called, ambient, or pass through modes. Some models actually let you vary between full transparency, and full noise cancellation. Some, like the Microsoft Surface (headphones), or the Sennheiser Ambeo smart headset, even have transparency amplified modes. Not quite a hearing aid, but probably enough to help someone with mild hearing loss.
I had never really liked closed back headphones, because already being totally blind, now they also block my hearing; completely isolating me. Now, with transparency mode, it’s almost like being able to switch between closed back and open back on the fly.
Transparency mode is not at all silly, or useless, like some might try to tell you; but instead, is the beginnings of augmented reality from an audio perspective.
2 thoughts on “My explanations about how headphones with noise cancellation and transparency modes work”
hello Kevin, I do not know if your blog emails allow you to receive replies, but thought I would try. I am here in Yakima Washington and help to edit the Washington Council of the blind Newsline quarterly publication. Would love to have you contribute some short articles for us, typically up to 1000 words or so, on technology. Or whatever you might feel like writing about. Unfortunately, we have no way to pay. All we can offer you is the platform. But I’m definitely enjoying your content on augmented reality. if you wanted you could reuse or expand on some of your previously published material and gain more audience. I have the Sennheiser Ambia smart headphones myself. They make amazing recordings. The general theme of our next issue which comes out in October is on literature, but anything goes, and we have different sections on blindness history, advocacy and legislation, technology and science ,entrepreneurship, lifestyle, features, the kids are all right for youth issues, you name it. I am also copying my co-editor Heather Meares on this note. Our next deadline for content is August 31. I can’t even remember how I found your blog originally. For some reason I thought maybe you lived in Washington state as well. Anyway, let me know your thoughts. I enjoy your writing regardless.
Respectfully, Reg George, CATIS Assistive technology specialist, Washington State Department of Services for the Blind
Life is what happens to you when you’re busy making other plans. Alan Saunders, John Lennon Sent from my self driving starship!
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I know Dave Edick maybe that’s how you know about me. I don’t write about the political or advocacy side of blindness only really the technology side. Maybe you could suggest one of my posts for your news letter or something or what you want me to expand on. Respectfully back, Kevin