The threshold of external interruption whereby listeners can effectively become immersed in a story or not is known as the
threshold.​

Yes.

Explanation:

Yes, threshold of external interruption indicates the situation whereby listeners can effectively  become immersed in a story or not is called the  threshold. In psychology, the level at which one starts to feel or react to something is known as threshold so we can say that in the story when the people immersed in the story we called it the threshold level of that story.

1.the hosts on two opposing mountains stood,  

2.thick as the foliage of the waving wood;  

3.between them an extensive valley lay,  

4.o'er which the gleaming armour pour'd the day,  

5.when from the camp of the philistine foes,

6. dreadful to view, a mighty warrior rose; in the dire deeds of bleeding battle skill'd,

1.c

2.a

3.d