The human ear responds more to frequencies between 500 Hz and 8 kHz and is less sensitive to very low-pitch or high-pitch noises. The frequency weightings used in sound level meters are often related to the response of the human ear, to ensure that the meter is measuring pretty much what you actually hear. It is extremely important that sound level measurements are made using the correct frequency weighting - usually A-weighting.
'Bonanza,' 'Trapper John, M.D.' star Pernell Roberts dies. Pernell Roberts portrayed Dr. John McIntyre on Trapper John, M.D..
Wednesday, January 27, 2010. Pernell Roberts, 81, a strapping actor who was an original cast member of the long-running TV western Bonanza and the star of the medical drama Trapper John, M.D., died of cancer Jan. 24 at his home in Malibu, Calif. Mr. Roberts was a Broadway and film veteran before joining the cast of Bonanza in 1959.