He laughs because an army is coming towards him, but he seems bored by his lack of fear. Suddenly, a woman cries out. Seyton, that is the servant, investigates and returns with the news that lady Macbeth is dead. Macbeth gives a speech about life. 

I have almost forgot the taste of fears;

ho quasi dimenticato il sapore della paura

The time has been, my senses would have cool'd

è passato il tempo in cui i miei sensi si sarebbero raggelati 

To hear a night-shriek; and my fell of hair

nell’udire un grido notturno, e i capelli mi 

Would at a dismal treatise rouse and stir

mi si sarebbero drizzati, tremanti a un trattato/racconto pauroso 

As life were in't: I have supp'd full with horrors;

come se in essi vi fosse vita: mi sono saziato di orrori (ho bevuto l’orrore goccio per goccio)

Direness, familiar to my slaughterous thoughts

Il terrore, familiare ai miei pensieri omicidi 

Cannot once start me.

non riesce più farmi sussultare

Here, Macbeth declares that he doesn’t feel because all the horrors he has been used to creating and when the servant comes in to his room to tell that a schrick of woman can be heard, Macbeth reacts seim that he doesn’t know what fear is and his living in a period when his sensis do not react to any piece of news. And he compares the present time to past time when infrant the terrible news his hear would fool because of the terrible piece of news. 

At the moment, on the contrary, it seems he has been used to competing with horrors he cannot react to anything. 

The language that Macbeth uses to express his fear is the language of senses language impression because it appears to one of the five senses and exactly the sense of taste. 

So, in the first line, the language of the senses impression where the play ride uses the lexical choice test contributes to make the nature of Macbeth more lovely. So, he considers his accing in time while in the past he would have been afraid to an ait schrick now he can't feel anymore, fear and at home.