Translation of muffle in Spanish

I started to speak Spanish because i had i boyfriend from Mexico. Especially I've never learned Spanish . I only listened and repeated what he spoke. Now i speak Spanish well but i need to learn grammar rules.
We stayed in this place for quite a while as it was the most spectacular place we have visited so far. It was unbelievable how much thought was put into construction of these magnificent sites.
Lunch was given at a family-run restaurant back in the valley. The headaches disappeared once were were back at 2000 meters. From there we continued to the Salar, a salt lake, mostly arid.