Haven't You Heard?

In relation to the previous thread titled "some newbies haven't heard", I bring the following information.

While at the VSC in Tucson this last March, I took along my sound level meter just for my own curosity to see what the different sound levels were from our favorite toys. I had the sound meter checked for accuracy just before I went to the VSC.

Sounds were recorded as follows.
Sound levels were taken at 10 to 15 feet distances, and I moved around to try to get a good reading.

Ignition 60 size range engines were by far the loudest. Charlie Bruce's Fox exceeded the meter's max scale at 120db Most others were around 116 t0 120db.

Old engines on glow, 60 size range , Were from 112 to 116 in the two cycle needle setting and 105 to 110 when four cycling. All the above were without any muffling of any kind.
More modern engines with tounge mufflers were in the 95 db range and open faced Fox 35s were 100 to 105 db.
All the modern engines that I took measurements on with TUBE type mufflers were under 90db. The quitest one that I found was an OS Max with a tube type that looked a little different than the other tubes and it checked out at 82 db.
Doctors all say that even short time exposure to loud noises can and does have long term detrimental effect on hearing.

SO DO AS N22222 SAYS AND USE EAR PROTECTION!!!!! Mine is shot already.

Bigiron

> In relation to the previous thread titled "some newbies
>haven't heard", I bring the following information.
>
> While at the VSC in Tucson this last March, I took along my
>sound level meter just for my own curosity to see what the
>different sound levels were from our favorite toys. I had
>the sound meter checked for accuracy just before I went to
>the VSC.
>
> Sounds were recorded as follows.
> Sound levels were taken at 10 to 15 feet distances, and I
>moved around to try to get a good reading.
>
> Ignition 60 size range engines were by far the loudest.
>Charlie Bruce's Fox exceeded the meter's max scale at 120db
>Most others were around 116 t0 120db.
>
> Old engines on glow, 60 size range , Were from 112 to 116
>in the two cycle needle setting and 105 to 110 when four
>cycling. All the above were without any muffling of any
>kind.
> More modern engines with tounge mufflers were in the 95 db
>range and open faced Fox 35s were 100 to 105 db.
> All the modern engines that I took measurements on with
>TUBE type mufflers were under 90db. The quitest one that I
>found was an OS Max with a tube type that looked a little
>different than the other tubes and it checked out at 82 db.
> Doctors all say that even short time exposure to loud
>noises can and does have long term detrimental effect on
>hearing.
>
> SO DO AS N22222 SAYS AND USE EAR PROTECTION!!!!! Mine is
>shot already.
>

I'm just amazed that we ever ran open exhaust, and never really noticed a problem. Now, when I hear even an unmuffled Fox, I have to go find something to hide behind, because I just can't take it.

Last time I had a audiometry, I found that I had hearing ~30-40 DB more sensitive than normal - except for an area around 150 Hz where it dipped down close to normal. 9000 rpm/60= 150 Hz.

Wear hearing protection, particularly when using unmuffled motors, or better yet, stop running them altogether - or you might be nostalgic for the days when you could still hear.

Some of the best lessons learned come from others. I now have a box of ear plugs in my field box for me and the boys.

Paul

Always learning from the experts!

I can't stand unmuffled engines ant more.

One of the good things I noticed when I had thos LA.46 was how quiet it runs.