Noun:

1. a football play is changed orally after both teams have assumed their positions at the line of scrimmage

Adjective:

1. heard or perceptible by the ear;

   "he spoke in an audible whisper"
   

distinctadj.明显的；清晰的；不同的；独特的

clearadj.清楚的；明确的；明白(某事)的；清晰的；清澈的；晴朗的；头脑清醒的v.清空；清除；澄清；放晴；使明确adv.清楚地；彻底地n.空地

plainadj.清楚的；简单的；坦白的；平常的；朴素的；纯的n.平原；广阔的区域adv.完全地；纯粹地

aloudadv.出声地；大声地

perceptibleadj.可察觉的；能感觉得到的；看得见的

noticeableadj.显而易见的；显著的；值得注意的

loudadj.大声的；吵闹的；引人注目的adv.大声地；响亮地

hearable听得见的,中听的

inaudibleadj.听不见的

1. He sang with no visible or audible strain.
   听上去和看起来，他唱得不费劲。
2. The shot was clearly audible in the silence.
   寂靜中枪声听得很清楚。
3. Their voices were audible to the neighbors.
   他们的声音邻居都听得到。
4. Her voice was scarcely audible above the noise of the wind.
   在风中她的声音几乎听不见。
5. A subdued impassioned murmur was audible in the room beyond.
   可以听得见那边屋子里有一阵低低的、激动的交谈声。