Some help with a science fair project

My son is in 7th grade and has to do a science fair project each year. This year he did a generic physics project and got no attention at the county fair. We both noticed that health/medical/biology type projects got more attention since many of the sponsors were medical type companies. Since he is hearing impaired we started brainstorming projects for next year that would be hearing related.

I have an iPhone and I’ve downloaded the UHear app. I checked his hearing with it and it gave a remarkably close approximation to his formal audiograms. We thought that a good project would involve getting volunteers to test their hearing and do a word recognition test both with just the headphones and then with a pair of earplugs blocking their ears to simulate a hearing loss. His message could be to not crank your iPod to try to protect your hearing.

A couple of questions.
What type of earplugs would block the most sound to simulate the worst hearing loss?

Would they only block low frequencies or all frequencies?

Is a noise induced hearing loss mostly a high frequency loss (thinking of loud music in headphones type loss)?

He’ll do his own research on the background info but if you all could point to some good sources of info to give him a good overview it will be helpful.

Is there a list of standard words used for a recognition test? I assume it will be words like pat and bat which sound similar. He plans to use a tape recorded test so it is the same for all volunteers. Should the word list go in a different order for the normal versus earplug tests?

For the hearing test we’ll get a pair of good quality headphones. Should they be noise canceling? Using earbuds his audiogram was a close match but I think it could be better with headphones. Plus you can’t use earbuds and earplugs.

Any other suggestions for his project?

This is his official audiogram

frequency Left Right
250 - 50 - 50
500 - 55 - 70
1000 - 75 - 75
2000 - 75 - 80
3000 - 75 - 75
4000 - 65 - 65
6000 - 60 - 60
8000 - 50 - 65

This is from UHear

frequency Left Right
250 - 60 - 70
500 - 60 - 60
1000 - 80 - 80
2000 - 75 - 90
4000 - 80 - 75
6000 - 70 - 75

The UHear doesn’t give decibel levels, just lists the loss so I interpolated using this scale
0 dB - 20 dB … normal hearing
20 dB - 40 dB … mild hearing loss
40 dB - 55 dB … moderate hearing loss
55 dB - 70 dB … moderately severe hearing loss
70 dB - 90 dB … severe hearing loss
>90 dB… profound hearing loss

Hi Maureen:

I am not an audiologist but work within the industry. You could contact Auditec of St. Louis, who supply the prerecorded cd’s that are used by audiologists/dispensers. Dr. Carver would probably answer some of your questions related to what words to use etc.
http://www.auditec.com/cgi/Auditec2010Catalogue.pdf

Etymotic Research makes a variety of Frequency shaping plugs that may work for your simulation, their website is http://www.etymotic.com/
http://www.etymotic.com/ephp/er20.aspx

Aero supplies Insert phones used in regular testing, I know you were looking at earphones, but thought I would include them as a reference.
http://www.e-a-r.com/auditorysystems/

Grason and Associates (Lee Grason, an excellent resource for some aspects of your project) He produces eartips, plugs filtered and non, would probably know exactly what you need for your project. His father was the founder of Grason Stadler, a leader in Audiometer etc. instruments for this industry. Welcome to Grason & Associates, LLC

If I think of more will post it up.

Good Luck

Just a quick update on this. This weekend was the county science fair. My son (in 8th grade now) did the project described above and won second place in the health and medical category. We are very proud of him. He learned a lot about his own hearing and hearing loss in general.