This unit is the most common unit used to express the front-to-back ratio of an antenna. A meteorological quantity called this unit relative to Z is a normalized expression for the equivalent reflectivity of a hydrometeor. The steepness of a filter’s transfer function is written as the change in this unit per decade or octave, which is a quantity called the roll-off. The frequency (10[1])at which gain drops off by approximately 3 of this unit determines the cutoff frequency. (10[1])In its most common application, a reference pressure equal to 20 micropascals defines a value of 0 for this unit. This unit is defined so that multiplying intensity (10[1])by a factor of 10 corresponds to an increase by 10 of this unit. For 10 points, name this unit that defines a logarithmic scale of sound intensity. ■END■