This sound spectrum spans about ten octaves. The top five octaves correspond to acoustic waves-the primordial sound of the universe, just 380,000 years into its existence.
这个声谱约有十个八度的跨度。前五个八度音阶与声波一致——仅存在了38万年的宇宙原声。
2
These unusual properties generally have to do with manipulating electromagnetic (EM) or acoustic waves; in this case, it is EM waves in the infrared spectrum
这些与众不同的性质一般都与控制电磁波或声波有关；在这种情况下，电磁波是处于红外波段的。
3
Road traffic noise reducing devices. test method for determining the acoustic performance. part 3 : normalized traffic noise spectrum.