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..
Doris Roberts was born in St. Louis, Missouri, on November 4, 1925. After roles on the stage and in film, in 1979, Roberts was cast on the hit TV series Angie, making her a recognizable celebrity for the first time.n 1995, Roberts landed the part of Marie Barone on Everybody Loves Raymond, a role for which she won four Emmy Awards for best supporting actress, in 2001, 2002, 2003 and 2005.