'A Quiet Place' is NOT a movie you can enjoy at home or by yourself. And it doesn't matter if you have a 72'' screen with theater grade surround sound, either. You MUST see it in a theater, surrounded by other people, to get the full effect. The thing that keeps mature people out theaters--phones, talking, popcorn munching--are gone fifteen minutes into the film. The tension, the absolute necessity of silence gains its hold and spreads quickly.
The bad guys--"Death Angels"-- are never really defined or explained. The film makers initially give viewers are only given what they need to know about them, and they attack anything that makes a sound loud enough for them to hear. Even wilderness scenes are devoid of sound. No birds, no insects, no sounds of nature save for the wind. The only sources of noise that exist are those that cannot be killed.
Details about where the Death Angels come from or what their beef with humanity is are left out. The're essentially giant tympannic membranes inside a powerful armored shell. Personally, I thought they resemble the skitters from Falling Skies. But if you find yourself nitpicking about that kind of thing then you're entirely missing the point of the movie (like the movie Signs). The point of the film is what do you do when the primary tool of your existence--the ability to speak and communicate--becomes a dangerous liability. This is a point brutally driven home early in the film. Even the exact number of Death Angels versus humans is never revealed.
The Abbotts do have a minor but relatively unique advantage not held by most other humans. Their daughter Regan (you know....like in The Excorcist) is congenitally deaf, so the rest of the family is already fluent in American Sign Language by the time the Death Angels arrive. Her inability hear is every bit an advantage as it is a disadvantage. The is accustomed to a world of silence, but she can't a creeper six feet behind her. She was fitted for a cochlear implant at some point, and her father is determined to find a working one for her. Yes, this proves significant later in the movie.
Aside from communication, the family's entire existence is centered around absolute silence. Their food is silently farmed, and all of their speaking activities are carried out below ground, including a "silence crech" (my own term) for a soundproof and oxygen-supplied cradle in which the expectant mother, Evelyn, will place her new child. Pretty? No, but survival isn't always pretty. It is, however, worthwhile.
The movie ends rather abruptly and unsatisfyingly, with the family accidentally discovering a way of defeating a single Death Angel. The family quickly notices that there are more on their way. We are left to assume that a loud, screetching laughterfest ensues.
Supposedly, there is 'A Quiet Place II' on the way. With sound now being part of humanity's arsenal, the sequel will have to give up it's primary tool of suspense building. My guess is that it'll be an entirely different kind of movie.