Explain the quote "A shriek had been heard by a neighbour during the night; suspicion of foul play had been aroused;..... premises."Explain those...

After the narrator has murdered the old man whose eye has
offended him to the point that he has felt he must be rid of it, he works to conceal the
body by dismembering it and placing the parts under the flooring the the chamber.  As
the four o'clock hour of the morning tolls, he finishes.  Then, there is a knock at his
door; still, the narrator is not nervous because he feels he has nothing to fear.  Three
policemen enter, reporting that there has been a report filed at the station that a
shriek was heard, and they have come to
investigate.

Cleverly, the narrator declares that he has
cried out in a nightmare. Embellishing his story, he tells the policemen that the old
man has gone to the country.  To lend verity his words, the narrator leads the police to
the man's empty room where he also shows them his valuables lest they believe a thief
has entered the house. Then, with great bravado, the narrator places chairs and invites
them to sit and visit as he is "singularly at ease."  However, the narrator has
discounted his conscience: 

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But ere long I felt myself getting pale and
wished them gone.  My head ached and I fancied a ringing in my
ears. 

Significantly, it is
then that the greater horror of the tale emerges.  For, Poe's narrator has descended
into madness and the horror of his deed takes possession of his mind.  Thus, in the
guilt and terror of his own madness, the narrator "hears" the beating of the old man's
heart, an unrelenting beating that persists in his own mental
torture,

Oh,
God!  What could I do?....

"Villains!" I shrieked. 
Disemble no more! I admit the
deed!...."

In his insanity
and psychological torment, Poe's narrator imagines that the policemen have acted in such
a way as to induce him to confess his guilt and betray himself.