In order to improve the acoustic characterization of breathy and whispery segments, we proposed a normalized breathiness power measure (NBP) by embedding a mid-frequency voicing measure (F1F3syn) in its formulation. A partial inverse filtering preprocessing and a sub-band periodicity-based frequency boundary selection approach were also proposed for improving the performance of the F1F3syn and NBP measures. Improvements from 70 to 83% on detection of breathy/whispery segments are achieved by the proposed NBP measure relative to previous methods, for a false detection rate of 10% in modal and rough segments.