Translation confusion

Question

I don't understanding the translation. For example why not use Domimos instead of "Hemos dormido", and why not anoche instead of "esta noche"?

Accepted Answer

Hola Pati
We chose to use this one in the lesson:

Hemos dormido muy poco esta noche por el ruido de los bares.
We slept very little last night because of the noise from the bars.

But we could have also said:

Anoche dormimos muy poco por el ruido de los bares.
We slept very little last night because of the noise from the bars.

They both mean the same, but when we use the time adverb "Anoche" we (in Spaninish minds) think of it as a completed time, as finished, and therefore use the preterite (dorminos).
However when we use "esta noche" also meaning "last night" somehow in Spanish minds we think of it as a time still connected to the present time when you speak, therefore triggering the present perfect (hemos dormido). 
Here is a lesson that talks about this. Have a look here.
I hope this clarified it for you.
Saludos
Inma

Answer

I am also confused about why "esta noche" would mean "last night instead of" this night". If "esta noche" means "last night" because of the present perfect, how would one say at 1 a.m. "we slept little this night because of the bars"?