Thread: Peltor Optime III earmuf specs

Makes me wonder what the frequencies are in a regular workshop.

Bandsaws, tables saws, sanders, that kind of thing.

I've seen notices of their volumes, but never their frequency, which is interesting.

Originally Posted by woodPixel

Makes me wonder what the frequencies are in a regular workshop.
Bandsaws, tables saws, sanders, that kind of thing.
I've seen notices of their volumes, but never their frequency, which is interesting.

Here we go - some quick and dirty measurements.
Ignore the text above the plots - just look at the graphs

1: Free running TS - no dust extraction.
Peak noise is in the 1 -3kHz range. Bout 80dB
Remember the ear is most sensitive to 1kHz so that why it's so annoying.
ts2.jpg

2: Wood lathe free wheeling with DC on
This is ALL DC noise - gets up to 85 dB at 500Hz.
Ducting is different than sander so the DC noise is not necessarily the same.

lathe2.jpg

3: 1m x 150 mm Belt sander free wheeling
This machine requires the DC to be running or it won't run
Broad spectrum noise (combo of DC and sand belt noise) reaching 80dB across the range
Most of the higher end noise is belt noise.
Sdander2.jpg


5" angle grinder grinder free wheeling
Highest frequency in the 4-5kHz range ~100dB
angleg3.jpg


Can do some spectrum while actually cutting and sanding if you are interested.

Fantastic information, Bob.

Would you please tell me the frequency of my wife's voice? That is the most annoying for me.


Sent from my iPhone using Tapatalk Pro

Its funny you should mention that Newboy.

My loving daughter is getting towards being a Psych. She always bounces her work off me to tidy it up. (My theory is that she thinks I am thick. If I can comprehend it, well...)

One of the most fascinating things I read was exactly your comment. I'll find the info, but the gist is that women's voices are smack bang in the range that most blokes loose their hearing in.

So, wifey complaining he is increasingly ignoring her? Nope, he literally doesn't hear her.

Edit - there was another which mentioned the specific frequencies that women's voices are pitched and (guessing) it being highly distracting or disruptive (??? Can't recall exact effect. 'll dig it up).



BTW BobL, isn't it interesting that the muffs don't protect so well at 2khz. Would this be so one can still hear being spoken too? For safety?

Originally Posted by Newboy

Fantastic information, Bob.

Would you please tell me the frequency of my wife's voice? That is the most annoying for me.

SWMBO has quite a husky, low-frequency voice. I only notice it when she is talking with other women.
Doesn't seem to change the annoyance factor though

BTW BobL, isn't it interesting that the muffs don't protect so well at 2khz. Would this be so one can still hear being spoken too? For safety?​

Could be, but in practice is doesn't matter - as long as the dB reduction is >36dB that's about as good as you are going to get. After that the skull will start conducting sound from the source direct to the inner ear. ie bypasses the ear canal And any muff.

The human ear is most sensitive at around 1kHz but age related hearing losses are usually at higher frequencies and those that end top muffling speech are in the 3-4 kHz range. These are important in differentiating between consonants/sounds like "c", "t", "sh" and "ch" etc

Originally Posted by woodPixel

Makes me wonder what the frequencies are in a regular workshop.

Bandsaws, tables saws, sanders, that kind of thing.

I've seen notices of their volumes, but never their frequency, which is interesting.

I wrote about the noises in mine: http://www.inthewoodshop.com/Powered...yWorkshop.html

Here is a re-print ...


Noise levels in my workshop








It seems appropriate to open the Power section with a word on safety, in this case hearing safety. I suffer from Tinnitus, and this is a result of decades of ignoring my hearing and workshop dangers. Fortunately, my Tinnitus is not too bad, and I have learned to dissociate from it. However, I would rather not have it. Take caution about the dangers of machine noise!!


A European Union directive on noise, issued in 2015, requires companies across the Continent to provide hearing protection for workplaces with a noise level higher than 80 dB. From 85 dB on, employees are required to wear hearing protection.


I measured several of the machines in my workshop. This was inspired by the recently completed installation of a new table saw and new hoses to the existing dust collector. Perhaps you can use this thread as a database/baseline for your machines and power tools to guide your own safety.

Noise levels were measured using an iPhone app, SPLnFFT. The measured ambient noise in my workshop was 40dB and my speech level 52-54dB. Listening to my favourite Internet jazz station (Jazz 24) via the workshop stereo produced as similar 52dB. Noise levels were recorded within 1m of the running machine.


Hand planing was a higher-than-expected 68dB.




Machines

The three main large machines I have:

* Hammer A3-31 Jointer-Thicknesser (silent head): 76dB …...This is tolerable for conversation
* Hammer N4400 Bandsaw: 78dB …...This is borderline – frankly, just too loud.
* Hammer K3 Tablesaw (12" blade combo blade by Stark): 93dB …... crazy loud!









Nova Voyager drill press (above): 44dB at 500 rpm; 48dB at 1000 rpm; 63dB at 2000 rpm.


The Nova Saturn lathe (below): 50dB at 500 rpm; 56dB at 1250 rpm; 63dB at 2500 rpm; 66dB at 5000 rpm.





Both the Nova machines are comfortable without hearing protection.

The Festool CT26E vacuum cleaner produced 75dB with the 27mm hose connected. Too loud for me.







Carbatec 2HP dust collector. This is fitted with a 1micron cannister filter via an Oneida Super Dust Deputy cyclone. Originally, this machine was connected by 4" hoses, and the noise level was subjectively LOUD (I did not measure it, but I would guesstimate around 95dB).


Changing to 5" hose appears to have dropped the level. Previously I could not switch it on without hearing protection (if one must, but I do not recommend). Now it was possible to talk over the machine! With 5" hoses, the DC measured 77dB.


I wonder if 6" hoses would lower the sound levels even more? Currently 5" is the largest I can go to without modifying the ports of the machines. I plan to upgrade all the hoses to rigid PVC when I eventually get a more powerful machine with a larger impellor.


My current dust control is supplemented with a 1/3 h.p. HAFCO overhead air cleaner, (and by opening the garage doors and blowing out the dust).


At the lowest speed, the sound level is 59dB, which makes an audible hum. The second speed is quite noticeable at 62dB, and the highest speed produces 64dB, which is intrusive. I tend to run this at the highest (noisiest) level at the end of a day, using a 4-hour timer. This does a decent job of scrubbing the air. It is just too noisy to have on generally, even with machines masking this, since the machines may not remain on very long.





Power Tools




The Carbatec 8" half-speed bench grinder (on the right) with 2 CBN wheels measured 67dB. This is reasonably comfortable without hearing protection.





The Rikon on the left, now set up with buffing wheels on both sides, produced 63dB. Comfortable.

The Carbatec 9x6" ¾ h.p. disk/belt sander combo measured 77 dB. I prefer to use my ear muffs here.











Elu 177e based router table 85dB with the router in the table …







… and 88dB when it was handheld (the big ‘un on the left) ...







This is comparable with the Mirka Ceros ROS, also 85dB …









Circular saws, like routers, are hideously noisy. This 7 ¼” 1300w (1 ¾ h.p.) NRG saw produces 97dB – the loudest tool in the workshop!







One needs to also factor in that the handheld power tools are used in conjunction with a vacuum cleaner, which adds its own noise.




Hearing Protection


My preferred earmuffs are the 3M Peltor, which lower the sound levels by 30dB. I have a couple of pairs at each end of the workshop.


Elipse dust mask and 3M Peltor


I also have a pair of Sensgard ZEMs. These are effective, but not as comfortable. On the other hand, they fold up and are the ones I will take to wood shows or other settings, where I need to demonstrate tool use and am situated near loud machines.





I tend to argue against the use of hearing protection which includes music or phone connection. The last thing we need when using machines is to be distracted from the task at hand … otherwise you might lose it.



Regards from Perth

Derek


November 2020

Originally Posted by derekcohen

I tend to argue against the use of hearing protection which includes music or phone connection. The last thing we need when using machines is to be distracted from the task at hand … otherwise you might lose it.

Up to a point...

For those of us with tinnitus (and I know you are a fellow sufferer) the silence when the DC stops with hearing protection on can be unbearable. For that reason, I have recently started using Bluetooth connected hearing protection.

Because the sound quality is so poor of the units I've so far used, I tend to play just noise. Meaning a combination of white/pink/brown noise. There are now numerous smart phone apps that can do this for little to zero cost.