Adobe 22011292 User Guide - Page 168

154 CHAPTER 8 Effects Menu - Edit View Notch Filter dialog Tones to Notch Here you may select and enter up to six frequencies to notch. Click in the checkbox to activate the box for entering a particular frequency (measured in Hz). You can apply different amounts of attenuation for each frequency by unchecking Fix Attenuations to at the bottom of the Notch Filter dialog. Then, enter the attenuation level (measured in dB) desired. Both the lower and upper DTMF tone sets (those used in the telephone system) can also be filtered as well. This is sometimes handy when preparing audio that could air on the radio. Just check which set of tones you wish to filter. Fix Attenuations to This allows you to set attenuation levels. • When this box is checked, all attenuation levels are the same. • Uncheck the box to set individual attenuation levels for each of the frequencies. Notch Width This drop-down control lets you select from three notch width presets. They range from Narrow for a second order notch filter, which can remove some side frequencies, to Super Narrow for a sixth order notch filter, which is very specific. It's recommended that you use no larger than 30dB attenuations for a Narrow setting, no more than 60dB for Very Narrow, and no more than 90dB for Super Narrow. Any more attenuation for the given notch width will result in a wide range of neighboring frequencies being removed as well. Presets Adobe Audition comes with several Notch Filter presets. More information on presets can be found in the "Looking at the Work Area" chapter. Preview Press the Preview button to audition the current Notch Filter setting before you apply it to the waveform. The selection is looped until you press the Stop button. Since Adobe Audition's Previews are dynamic, this gives you the opportunity to make and hear processing adjustments as the selection is continuously played.