Road noise in a rental car


#1

My company has me in rental cars quite often. I have to drive long distances in these things and the road noise wouldn’t be much of a problem if I didn’t have to endure it for hours at a time. There are certain sections of the road that are worse. I have measured as high as 80 dB; one website indicates that ear protection should be used at 75 dB as a government requirement. A measurement of 80 would be well over twice as loud as 75. I try to choose quieter routes, but most of the time the levels are mostly over 70 dB. Obviously I can’t do anything major to a rental car. Can I do something over the floor mats or ??? that is portable?


#2

There’s no way to easily retrofit a rental car for noise. Earplugs are your only hope. Or just stuff some cotton in your ears.

https://www.pegasusautoracing.com/group.asp?GroupID=HEARING

“But earplugs won’t let me hear my car or the cars around me!
Earplugs still allow you to hear, just at a reduced volume. Earplugs can actually make some of the more subtle sounds easier to hear! By keeping the loud noises at a level your ears can handle, quieter noises are able to come through. With earplugs, you can still hear and identify noises such as a cracked header, knocking rod, or worn wheel bearing. Without earplugs, all you hear is a dull roar – followed by a sharp ringing sound.”


#3

The OSHA standards start at 90 db for an eight hour day. I wouldn’t worry about 80 db. And that web site talking about 75 db is wrong.


#4

Electronic noise cancelling hearing protection is available and works very well. OSHA standard is 90 db for 8 hours.


#5

Problem is, noise cancelling headphones work so well that they could be dangerous when driving. Ear plugs will filter some, but not all, noise and so be less dangerous.

Not to mention, wearing headphones while driving in most states is illegal and a good way to get pulled over.


#6
"noise cancelling headphones work so well that they could be dangerous when driving" +1

Being able to hear sirens and klaxon horns from emergency vehicles is vital for everyone’s safety.


#7

The OSHA standard is a TWA (time weighted average) of 85 dB for 8 hours or 90 dB for 4 hours. This is the level for which hearing protection is required and the hearing protection must bring the 8 hour TWA below the 85 dB threshold. 80 dB at 70 mph is actually pretty good as some cars hit 90 dB or higher.

The 75 dB figure may be the TWA where annual hearing tests are required, I’m not sure, its been over 10 years since I worked in industrial safety and environmental compliance, but I am sure about the 85 dB for hearing protection. A lot of companies will require hearing protection at lower levels for a margin of safety. One company I worked for set it at 75 dB, another set it at 80 dB.


#8

keith You are 100% correct for 10 years ago. It has been over 6 years since I had to stay current on OSHA regulations. I remembered TWA of 85 dB for 8 hours. I checked OSHA/Hearing Protection and the current chart is 90 dB for 8 hours , 92 dB for 6 hours… I didn’t read farther as I was only concerned with the change from 85 to 90. That is a significant change! Why? I have no idea but could easily suspect more Big Business running our Government.


#9

Headphones are illegal in some states. I imagine that hearing protection would be illegal too. If you use hearing protection, use ear inserts (foam, Sweedish wool) so that you don’t get busted if you are driving where it is illegal. Not many prohibits it, but a few do.


#10

As far as I know headphones are still illegal in my State. Of course this law was passed to deal with stereo headphones. Now days there are so many idiots driving with their Ipod earbuds inserted and the volume at 11 it would be difficult to enforce. On second thought I don’t think the electronic noise cancelling headphones would help the OP. The ones I have experience with only cancel sounds above a certain threshold. I would guess 90 dB. They somehow enhance sounds below the threshold to simulate not wearing hearing protection. I agree with your suggestion of inexpensive foam earplugs.


#11

Here’s a list of state laws pertaining to headsets.

http://drivinglaws.aaa.com/laws/headsets/


#12

The NRA tested some new noise canceling headphones. They canceled anything out over 85 but let all the other noise in. So they were perfect for range use to cancel out range noise, but allowed conversations to be heard. The cost was about $475 so if it bothers you that much I’ll look the name up, otherwise maybe check the cars you are renting a little more. I’ve never had any problem with rentals and I usually get the smallest cheapest.

Edit: $499 from ghoststryke.com


#13

Maybe I am overly sensitive at this level, but when I get to my destination the noise has left me with my head numb and it is difficult to do my work. I have tried earplugs, but it would be nice to hear music or the radio, too. With earplugs I only hear the highlights of the music.


#14

Regardless of state laws, earbuds from your ipod are hard to detect and they do help remove some outside noise. I did that on long trips in my Saturn. I too am sensitive to higher noise levels. I have tinnitus from working around jets for so many years, even though I always wore hearing protection.

I wear ear plugs in my truck because it is very loud.

You might also talk with your supervisor or companies safety officer about your problem. Maybe they will authorize an upgrade in your rental cars to at least mid size. Most of those cars are a lot quieter than the compacts. This is what you really wanted to hear isn’t it?


#15

I doubt there is anything effective you can do to a rental car. Noise reduction in cars is not simple and adds quite a bit of weight to modern cars. I’m actually surprised you’re so bothered as current cars are much quieter than older ones. Much better aerodynamics have reduced wind noise, engine noise is reduced by designing blocks to vibrate less and all the plastic that covers the engine, suspension noise is reduced with subframes and soft bushings, and there is all there are all kinds of mats and coatings to keep sound out of the passenger compartment. A handful of cars even provide active noise cancellation (low frequencies only) even when the sound system is off. That can be remarkably effective. Direct injection systems are somewhat noisy and some tires may be. That you hear this only at certain speeds suggests tire noise. Some pavements just cause vibration with certain tires. All you can really do is try different kinds of rental cars to see what works. Unfortunately, the quietest cars are usually the larger and more expensive models. Good luck.


#16

keith I did my first 6 years in the Army National Guard flying in OV-1 Mohawks. One of only 2 Army aircraft which required the sound protective helmet plus earplugs. The other aircraft was the CH-47 Chinook helicopter. The OV-1’s propellers were louder but the turbine engines were a higher frequency. I also suffer from high frequency hearing loss from the gas turbine engines. My last 24 Army years were spent around and in them with a combination of rotary and fixed wing.


#17

With the data you’ve collected perhaps you should ask your company to upgrade your rental vehicles.

There’s also the outside possibility that you’re developing a medical condition. Just to be on the safe side, it might be a good idea to have your general practitioner refer you to an audiologist for testing.


#18

Bing " The NRA tested some new noise canceling headphones. They canceled anything out over 85 but let all the other noise in. So they were perfect for range use to cancel out range noise, but allowed conversations to be heard. The cost was about $475 so if it bothers you that much I’ll look the name up, otherwise maybe check the cars you are renting a little more. I’ve never had any problem with rentals and I usually get the smallest cheapest. Edit: $499 from ghoststryke.com" The brand I used in the military was Peltor and were about $200. Of course that was about 6 years ago. As I stated in my earlier post they would be expensive and not solve the OP’s complaint of noise 80 dB or less


#19

Is there anyway to switch the cars? If they are rental, then the commitment should be short term. Just have them rent a Camry, the most quiet economy mid-size sedan.


#20

Over inflated tires can transmit more road noise.
Get an accurate tire gauge (dial or digital).
Check the tire pressure and compare it to the rating printed on the sicker in the driver’s door frame.
If the tires are hot from driving pressure might be about 5 pounds over.

You’d be surprised how many trained gorillas (learned that term from James Garner) fill tires to 50psi instead of 35.