If FREQ_REPLACE_INTERP is note selected, the amplitude spectrum of the frequency band is attenuated by a factor specified by the ATTEN_FACTOR parameter. If ATTEN_FACTOR = 0, the frequency band is zeroed. Typically, zero is used to completely remove the noisy frequencies. However, if you wish to save a small portion of the noise so the frequency band is not entirely zeroed, specify a small number for the ATTEN_FACTOR parameter (.0001 = 80 dB). A two sample cosine-squared taper (factors of .75 and .25 of the attenuation factor) is applied on both sides of the attenuated amplitude spectrum. If the default option of CENTER option of the FREQ_BAND_TAPER parameter is chosen, the taper is center around the boundary of the anomalous band. This means that the taper begins at the nearest sample of each adjacent frequency band. For example, Figure 9 shows an anomalous frequency band composed of frequencies 8, 9, 10, and 11 Hz. The attenuation filter is applied such that the taper is applied to frequencies 7 and 8, and frequencies 11 and 12, and that frequencies 9 and 10 are attenuated at the specified ATTEN_FACTOR parameter value (in this case zero). Note that frequency 7 is part of the frequency band preceding anomalous band and frequency 12 is part of the frequency band following the anomalous band.