| |||
| 不可听见的声音 | |||
| 亚声 | |||
| ★ 次声 | |||
| 次声频的 | |||
| 亚音频 | |||
| 次声 (波); 亚声 (波，同 infrasonic sound) | |||
| |||
| 超低频音 (低于15赫兹，人耳无法识别的空气振动频率。) | |||
| English thesaurus | |||
| |||
| Very low-frequency sound which can travel long distances and easily penetrate most buildings and vehicles | |||
|
infrasound : 6 phrases in 3 subjects |
| Air defense | 1 |
| Space | 1 |
| Technology | 4 |