You made a good point about how people respond to certain sounds but to be absolutely clear, there is no slant to the study. The fun is in finding out the answer, not having an answer and designing a study to prove it - that would be lame.

 

nicely macabre, but the point is well taken!

 

Sorry Fury, but your second paragraph of your opening post negates what you just said.

" am a PhD student in human factors and ergonomics and one of the areas of research in this field is safety and warning systems. I had a colleague recently conduct a study to investigate the safety of quite hybrid cars. He found that these cars are too quiet and can be a safety hazard for pedestrians. Other research has supported this. So, we can start with the idea that at least some amount of noise is important for vehicles. "

 

Glad I could help. I looked at similar issues for a presentation I did a couple years ago at a public administration conference. I'll have to find it, but NHTSA had something on pipe statistics that was useful. Unfortunately their dataset wasn't good enough to prove anything, but it will help at least with basic accident stats. I'll see if I can find it.

I got you ... if nothing else you could do an initial study relying on Hotelling's T. Maybe one dichotomous independent variable (volume of pipe noise) and then multiple dependent variables. Let's say putting someone in a car with windows up, windows down, radio on, radio off, etc., and then pull your significance findings out of it. Still staying with multivariate, so we accomplish some of the same goals (which takes care of the validity issue I was concerned with), and in the end you'll have a little easier time with the overall analysis for variance.

That would certainly set up some potential funding as well. I'm wondering how much the pipe/muffler manufacturers would kick in to fight the EPA noise standards a bit. I'm not fan of really loud pipes, but the current enforcement approach is starting to look a little Draconian.

You could have gone all night without mentioning IRB ... [shivers up my spine]. Those good-intention folks have ruined more fun studies.

Here's an alternative. If you've got a local high school or vocational school that offers auto shop then you might have a double-set of "volunteers." That gives you a closed shop to set up your testing laboratory and potentially a set of test subjects. The alternative is to find a local garage that will let you setup there for a couple days and use volunteers from the campus.

Here's what I'd do ...

1) Put the subject in the car.
2) Put a motorcycle behind them.
3) With baffles in and car windows up, rev the bike to 2500 RPM.
4) with baffles out and car windows up, rev the bike to 2500 RPM.
5) Repeat 3 & 4 changing the variables (windows up, radio on; windows down, radio on).

Using a dB meter you can measure the noise level prior to starting the testing. Now you've got your base for the baffles in, out, windows up, down, etc. Then just run 40 to 80 folks through the process. When they are done have them answer a short survey. Code everything for SPSS (or your stats program of choice) and you're flying with a decent little dataset.

I think you're on to something with a variance analysis, and this would fit fairly well for a quick & dirty study. Then you can use this to go after some funding to do a larger study. The IRB shouldn't have a big problem with the study.

 

I watched an interesting show on TV this weekend. It was a study tracking drivers eye movements using special glasses that track and pinpoint eye movement while several different cohort groups drove an actual car in a wrap around simulator. The car was real, but didn't move, the three screens surrounding the car simulate movement, auto sounds etc...

Using a device like this would get you your hard data.
You could tell the subjects this is "just a driving study" to reduce bias. Have them go through a course several times to get a baseline. Then add motorcycle exhaust noise.

You could see if their baseline eye movement changed. Due to motorcycle exhaust noise. Further, in a simulator, you could change the location and volume of the exhaust noise.

For example, if you designed 4 courses with a few core study obstacles you could measure whether eye movement (and possibly brake application and steering) were significantly different when noise was applied.

For example...the person is driving past a panel truck parked on the side of the road. Track their eye movemets for several passes as a baseline. Then pull a motorcycle out from behind the panel truck, with no exhaust noise, with EPA level and with "loud pipe" level to see how much if any their baseline eye tracking changed.

I would think you could only get one noise run per subject as the subjects would be biased aka looking for motorcycles after the first close call.

Just some random thoughts

 

Couple questions first, do U even ride or own a bike??

IF U R doing a research, why does it bother U to hear opinions that U say are boring??? research to me includes having + and - comments...

Not sure what Ur HF is, and I don't have a PHD, All I have is 21 yrs teaching all areas of all Health & Safety classes to over 10k UAW members and to over 1K MGT.
Then my last 7 years I was appointed and approved by International as a UAW-GM H&S REP.
Also assigned to me was the local Ergonomics team, In your studying then U know that UAW-and the BIG THREE were leaders and set the benchmark in many areas in ERGO and HEALTH & SAFETY.
We the UAW & Mgt. always said the OHSA istandards are just the minimum. This was just to give a brief background.

OSHA's noise standard is for the workplace. I don't have expertise in NHTS or who ever controls noise on public road, but it can't be the same as the work place because the time exposure is not there to warrant hearing protection. the riders exposure would on some bikes be over the limits I enforced. and should wear PPE. but again this is on the road not in work place, cant enforce...

Our serious FT accidents increased when we were forced to go ELC on our FT's
because the gas put off fumes and CO. and then people just walked in front of them, "DIDN"T HEAR IT" was usually answer.

So talk to people who are on both side of the fence, don't feel that either is boring if you want true results.

The best input is if U ride U should already know its better to be heard than not be heard...

In the last two years I 've had at least 20 times the pipes have warned others of my present better than the horn would have.
The last time was just yesterday.
4 lane by-pass. 45 speed limit, as I was in left lane at 48mph and Grandma in the right lane, I'am about even with her back door, then she started to pull left, right into me, I gassed it and severed left or she would have got me. U should also know about habits, I did't first beep my horn, My first instinct was to G.T.F@@k. out of there...
Point is, she heard me before she saw me and she severed back into her lane.

At the next stop light she apogilzied and said she did't see me till she heard me......

 

This may seem off subject ... ut I have always wondered why Motorcycles have little timid horns , yet a mack truck and the like have Massive horns ?? Jake

 

So... if you get this study acknowledged and accepted... does that mean my insurance premiums will go down for loud pipes?

 

Dam, I guess no good idea go's unpunished, are you happy now Chopfury

 

Long before I ever heard all the excuses why people liked loud pipes,animals,being noticed,safety,etc,for me it was the pure joy of the large bore two cylinder ground pounder.Back then I thought there was more horse power to be gained.Wrong! actually lose power.Also made me feel different making all that noise,like, look it's me.No matter,the bottom line is a Harley Davidson motor, by it's design,has a sound like no other,especially through straight pipes,or a tuned exhaust.Will look forward to reading what your study produces.