Home » Amateur Radio » Fletcher Munson Curves In Ham Radio

Fletcher-Munson

The Fletcher Munson curves are one of many sets of equal-loudness contours for the human ear, determined experimentally by Harvey Fletcher and Wilden A. Munson, and reported in a 1933 paper entitled “Loudness, its definition, measurement and calculation” in the Journal of the Acoustic Society of America. The first research on the topic of how the ear hears different frequencies at different levels was conducted by Fletcher and Munson in 1933. In 1937 they created the first equal-loudness curves.

Humans don’t hear all frequencies of sound at the same level. That is, our ears are more sensitive to some frequencies and less sensitive to other frequencies. In the early 1930’s Dr. Fletcher and Dr. Munson, audio pioneers at Bell Labs discovered that the human ear hears differnetly at varioius loundness levels. At 130+ dB SPL we hear almost flat. But we hear lows and highs poorly at lower volumes (lower SPL) and it gets worse the softer the sound. To complicate matters further we all loose our hearing above 14,000 Hz as we age!

The important thing to understand about sound is the volume (in SPL) affects your perception of bass and treble response significantly. What sounds quiet one way, sounds different loud. The same thing is true for sources and microphones. A mic that sounds good at low level may sound terrible at high level! Fletcher-Munson also discovered that the dynamic range of the human ear was 120 dB!

How does this relate to Ham Radio After several years of experimenting and listening, the Heil Sound team discovered that most of the old line favorites have their frequency response in the wrong place. Just about every dynamic microphone has a mid-range response peak that is in the wrong place.

To fix this problem of audio quality and sound we use the knowledge of Fletcher Munson Curve.

  • Use an equalizer to equalize the sound to make the sound better
  • Get away from using a ham mic on rigs as almost all hand mics on rigs are made by the same two companies
  • Don’t just turn up your mic gain to get threw pileups during contest focus on audio quality studies have showed that during a pile up the operator will pick the best quality sound over the loudest call.

Comments

comments

Latest

Apple Hardware Week
chips The Technology Behind a Live Casino
30 year internet The Internet turns 30 – pondering on the message from its maker
mac-skin The Perfect Gifts for the Tech-Friend in Your Life
travel mug Item of the Day – Bubba HERO Fresh Insulated Stainless Steel Travel Mug

Follow Us

Visit Us On TwitterVisit Us On FacebookVisit Us On GooglePlusVisit Us On PinterestVisit Us On YoutubeCheck Our Feed

Tech Geek Today

MonTueWedThuFriSatSun
    123
45678910
11121314151617
18192021222324
25262728293031
       
    123
45678910
11121314151617
18192021222324
25262728   
       
 123456
78910111213
21222324252627
28293031   
       
     12
3456789
10111213141516
17181920212223
24252627282930
31      
   1234
567891011
12131415161718
19202122232425
2627282930  
       
1234567
891011121314
15161718192021
22232425262728
293031    
       
     12
3456789
10111213141516
17181920212223
       
  12345
6789101112
13141516171819
20212223242526
2728293031  
       
      1
2345678
16171819202122
23242526272829
3031     
    123
45678910
11121314151617
18192021222324
252627282930 
       
 123456
78910111213
21222324252627
28293031   
       
      1
2345678
16171819202122
23242526272829
30      
   1234
567891011
12131415161718
262728293031 
       
   1234
567891011
12131415161718
19202122232425
262728    
       
1234567
891011121314
22232425262728
293031    
       
    123
45678910
11121314151617
18192021222324
25262728293031
       
  12345
6789101112
20212223242526
27282930   
       
      1
9101112131415
16171819202122
23242526272829
3031     
    123
45678910
11121314151617
252627282930 
       
 123456
78910111213
14151617181920
21222324252627
28293031   
       

New Book Now Available

My new book is now available on LeanPub. Buy it once and get lifetime updates everytime it’s updated. You never need to buy it again.

Buy Now