Question About Automobile Noise Cancellation Technology

[Imjusthappytobehere]

I have a painful condition called Hyperacusis (high sensitivity to sound). This causes me a lot of ear pain when driving an automobile because of the natural noise thats associated with driving. I'm wondering if anyone here has any experience with active noise cancellation that may some how be wired in to the stereo system of an automobile. One of the Japanese auto makers has this type of system installed in one of their automobiles but its only available in the models destined to Japan and not available to the US. And I couldn't afford a new automobile anyway. I'm hoping to find a low budget way to duplicate the Japan Auto manufactures system that can be wired into any other automobile that I can afford. My Hyperacusis doesn't cause me to much discomfort as long as noise levels doesn't rise above 70 to 75 db so the system doesn't have to remove all noise, it just has to lower it to 70 or 75 db. The noise that bothers me the most is the mechanical noise of the engine and the vibration it can cause inside the automobile.
I have a set of headphones with this type of active noise cancellation technology built into them so I'm wondering if there is a way to tap into the circuitry and modify it to be wired into the automobile audio system. I know it couldn't be as easy as that because I'm sure its a bit more complicated but when one has Hyperacusis one will do a lot o hoping this type of technology will some day be affordable to those that really cant afford a lot but needs it.
Thanks so much for your time and any and all help would be greatly appreciated.

[Bigglez]

The noise that bothers me the most is the mechanical noise of the engine and the vibration it can cause inside the automobile.

So this is more than audio noise? Even blocking
your ears would not remove the vibrations conducted
through your bones. Have you tried ear plugs (as an
experiment)?

I have a set of headphones with this type of active noise cancellation technology built into them so I'm wondering if there is a way to tap into the circuitry and modify it to be wired into the automobile audio system.

I noticed that many frequent airline passengers use the
Bose brand noise-cancelling headphones along with
either the in seat audio or their own personal
electronics. I conclude that these h'phones have line
level audio inputs to provide noise-cancelling of
ambient noise only.

I wonder if a driver is permitted to operate a vehicle
with total or partial sound masking? In California it is
required to use a hands-free device with cellphones
while driving, and while many have single ear phones
others double as stereo music players and don't. I
see that emergency vehicle drivers and crew often
wear headphones (to counter their own sirens?).

[Robert Reed]

Why is your engine and such producing so much noise? I have had new cars, old cars and everything in between and the engine noise was so low it was masked off tenfold by normal road noise (which BTW wasn't that bad on normal highways).
For me, sitting back and listening to good music in the proper environment is one of the great joys of life. On the other hand, driving a car on todays highways is a totally different story. I rarely even play the radio, as my total concentration is focused on the highway and unusual sounds that occur so as to alert me to a dangerous change that may be taking place. This has saved my butt on more than a few occasions.
I can sympathise with your condition, but i wouldn't blank out to much of the ambient road noise.

[dtief]

Lower frequencies are easier to cancel than higher. Below 100Hz low.
Here's a simplified version of acoustic noise cancellation:

A microphone located so that it picks up the noise. Another located near your ears. A speaker is in the acoustic space. A DSP calculates the phase and amplitude of the noise signal using an adaptive filter, sends a signal that when sent through the speaker is equal and opposite of the sound at the mic near your ear. The DSP uses the signal from that mic to make corrections to the filter.

Kind of, but not exactly like a graphic equalizer with 1 or 2 thousand bands, and an adjustable delay for each band. The adaptive part adjusts the delay and amount of boost or cut for each frequency.

The nulled (quiet) area is small, and if you move out of it, the effect is gone. In fact, there will be places that are noisier.

This is pretty easy with headphones, because the relative locations of the mic, speakers and ears don't change when you move your head.

[Imjusthappytobehere]

The noise that bothers me the most is the mechanical noise of the engine and the vibration it can cause inside the automobile.

So this is more than audio noise? Even blocking
your ears would not remove the vibrations conducted
through your bones. Have you tried ear plugs (as an
experiment)?


Yes ear plugs help some but nothing I've found helps with the sound thats conducted through the bones around the ear plugs.
Plus I also have a condition of severe Tinnitus (ringing in the ears at
100 db). Tinnitus goes hand in hand with Hyperacusis. When ear plugs are used Tinnitus becomes madding to the mind because with Tinnitus the only way I can cope with it is to have an external sound source to focus on. The external sound source (but no more than Hyperacusis pain causing 75 db) draws the minds attention away from the Tinnitus.

I have a set of headphones with this type of active noise cancellation technology built into them so I'm wondering if there is a way to tap into the circuitry and modify it to be wired into the automobile audio system.

I noticed that many frequent airline passengers use the
Bose brand noise-cancelling headphones along with
either the in seat audio or their own personal
electronics. I conclude that these h'phones have line
level audio inputs to provide noise-cancelling of
ambient noise only.

I'm really glad you mentioned that the Bose may have a line level input for external audio sources because this would be a step forward in possibly wiring this technology into an automobiles audio system. The noise canceling system thats offered as an option on the Japan destined only automobile uses a circuitry that monitors the audio source such as a radio station broadcast and at the same time monitors the outside road noise by microphone for any noise thats different than the radio broadcast, then sends out an anti noise signal through the audio systems speakers that will only cancel out the outside road noise leaving the radio broadcast perfectly normal to be enjoyed by the occupants inside the automobile. I guess this would seem a gargantuous task for a do it your self project but maybe with the use of affordable noise canceling technology such as the Bose brand headphones it will bring a project such as this closer to accomplishment.
The obvious question would be, Why not just use the Bose headphones by them selfs and listen to the radio through the headphones to mask the Tinnitus? Its a little hard to explain this but a person that has Hyperacusis is able to deal with slow moving low frequency sound waves a lot better than fast moving high frequency sound waves. The speakers in headphones because of their small size produce the faster moving high frequency sound waves much more efficiently than the needed slow moving low frequency sound waves that can be better tolerated by sufferers of Hyperacusis. An automobiles audio system uses much larger speakers that are able to better produce the Hyperacusis suffers much needed slower moving sound frequency's. This is why I'm trying to incorporate an existing noise canceling technology into an automobiles audio system so I can have the needed slower moving audio sound to help deal with the Tinnitus but at the same time reduce external road noise sounds such as tractor trailers and other louder automobiles that one with Hyperacusis must deal with on the road ways .
Another reason for desiring an audio noise canceling system of this type is a Tinnitus and Hyperacusis suffers life is so dramatically altered (destroyed) that any simulative situation to a normal life is desperately desired, dreamed of and wished (basically prayed) for. And a system of this type would do wonders for a chance of bringing some normalcy back to my life.

The next paragraph below is another reason ear plugs would be hard to use all the time when operating a n automobile
A system of the type I'm speaking of would allow some (no more than 70 or 75 db) of the external road noise to be heard by the operator of the automobile so that a noise that maybe needed to be heard by an automobile operator (think ambulance siren) can be heard.

I wonder if a driver is permitted to operate a vehicle
with total or partial sound masking? In California it is
required to use a hands-free device with cellphones
while driving, and while many have single ear phones
others double as stereo music players and don't. I
see that emergency vehicle drivers and crew often
wear headphones (to counter their own sirens?).

[Imjusthappytobehere]

The above post by me in reply to Bigglez includes my replies to his replies.
Sorry I'm not use to posting a lot. And I see others have replied to this pos and I cant thank all of you enough for your interest and concern for my situation.

[Bigglez]

The above post by me in reply to Bigglez includes my replies to his replies.
Sorry I'm not use to posting a lot. And I see others have replied to this pos and I cant thank all of you enough for your interest and concern for my situation.

You can still edit your earlier post, if you wish.
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for Code to make the embedded quote tags show up here).

Some of this group's frequent posters choose not to
use these tools. Threads that do are much easier to
follow, though.

[dtief]

On the idea of wearing headphones that block sound while driving - I can't say for sure in all states, but some do have laws against it. Primary reason is they want drivers to be able to hear emergency vehicle sirens, horns, etc.

[mojorizing]

Hello,
I’m somewhat versed on hyperacusis/ tinnitus because my wife has both due to a car accident a few years ago (airbags going off in a closed vehicle). I’m not an acoustical expert, only an engineer, but these are my thoughts:

Firstly, my wife treats herself with ear buds that generate white (or it might be pink) noise to eventually raise her pain threshold for louder noises. You’re probably aware of this, and are using something similar, but if not, check this out because it’s a treatment. Driving her car doesn’t bother her, but if it rains while she’s driving, the sound of the raindrops hitting the windshield causes her pain. She can’t wear noise-canceling headphones because the compression over her ears is too painful.

Active noise cancellation is most effective when there’s one freq. from one source. The algorithm to sample, process, and broadcast a waveform that is counteractive is relatively simple. Now throw in a full spectrum of noise generated by the tires and engine, transmitted through the frame and arriving to the driver’s ear involves something more complex. I would think that the car designers optimized sensor locations in the frame, filtered out the major contributor of noise energy in terms of frequencies, found where these frequencies emanated from and by what route they were transmitted to the drivers ear, and then calculated (amplitude/freq.) the exact noise to generate at each speaker so that the offending waveform coming from the front right tire/suspension unit, for instance, is cancelled out by the speaker in the passenger’s door. To simply add this to any car without all the testing and tuning might aggravate things and actually cause the noise level to increase as the waveforms become in phase. The reason noise canceling headphones work so well is because the noise is sampled so near the ear canal, and the corrective waveform is applied there also. I don’t think there will be a successful after-market noise canceling system for autos available in the near future.

Most of the noise in most vehicles is the road noise generated by the tire treads contacting on the road. Do you have an aggressive tread on your tires? Once person gets hyperacusis, they usually trade in their present car for the quietest vehicle they can find and afford.

I hope someone here can help, because I see the misery you’re going through.

Good Luck,
Kevin