The sonic signature needs to keep the treble detail, but increase the frequency spectrum and add a more full sound.
声音特色方面，要保持高音的细节，但增加频响宽度，增加更多的饱满的声音。
2
The longitudinal distributions of source intensity spectrum of several typical ships is given on the basis of time frequency analysis of the passage signature of ship radiated noises.
籍助对舰船噪声通过特性信号的时频分析，得到了若干典型舰船的噪声源强度谱纵向分布特性。
3
All of those are important for choice signature sequences in the spectrum code-division multiple-access communication systems.