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jewelry? To read a safety-related article that includes such a picture is truly sad.

Charles Sheaff

Keene, NH

In the pboto in question we were measuring the noise level of a blade, and a guard would have interfered with our readings. But you're quite right about the other procedures. It was simply an oversight on our part.

Deconstructing Decibels

Re: "Quiet Blades" (aw #34). The article states that "decreasing loudness by 3 dB cuts the sound intensity in half." This is essentially inaccurate. Loudness does not linearly correlate to sound intensity. A 3-dB difference equates to a reduction of acoustic energy by half; however, it is generally regarded that a 10-dB difference in energy levels is required in order to be sensed as a reduction in loudness by half.

Having been led to believe these blades offer dramatic improvements over conventional blades, users may tend to think their particular blades arc defective (if their ears don't discern such a difference!.

Marl; Bailey Piedmont, CA

You're right. The 3-dB reduction in sound intensity does not halve the loudness of the sound you hear. But "loudness," like "sweetness" or "beauty", is a subjective term that doesn't precisely indicate bow harmful a sound is. In the final analysis, reducing sound intensity by 3 dB cuts the power of 0*e sound in half and that significantly reduces harm to your ears.

Fine Figure

I truly enjoyed Monroe Robinson's article on "Wood Figure in Design** (aw *32). The subject is seldom discussed in woodworking books and magazines, but it is most important in achieving your best results.

Jose A. Mari Mutt Mayaguez, Puerto Rico

What's on your mind? We value your comments, complaints and corrections. Send your letters to: "Editor," American Woodworker, 33 E Minor St., Emmaus, FA 18098, or telephone your message to us at 215-967-7776. FAX: (215) 967-8956.



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Wood Working for Amateur Craftsman

Wood Working for Amateur Craftsman

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