Taxi Driver

In the film Taxi Driver, I have noticed that there is a lack of suspense for moments that generally would have it. For instance, when Travis goes on his murder spree there is no buildup of any kind. The viewer just sees Travis make small talk with Sport and then all of sudden pull his gun out and fires. In a typical modern day movie we expect the guy with the gun to have some cheesy line or a monologue about how he is going to kill the person. This continues when he just goes into the house and starts firing at the other guy shooting his hand partially off. While watching this scene there was also a lack of non-diegetic sound which, in my opinion is a staple of action packed scenes. Although it was odd for me to see, I feel the lack of non-diegetic sound adds to the scene as a whole.