I will talk about and explain how these four inventions: the microphone, the typewriter, the braille reading system, and the sewing machine helped make life easier.
The microphone is a device that amplifies sound. When the sound waves enter the microphone, it strikes a magnet causing the magnet to vibrate. Which in turn amplifies the voices. There are many different types of microphones. They can be made for amplifying soft stringed instruments, loud brass instruments, or they can be made for amplifying voices. The microphone has made life easier because when one is at concerts or plays if you are at the back one can not really hear the voices. But with the microphone, one can hear the voices easily.
The typewriter is a machine used for typing. When someone hits a key, the hammer for that key swings down, and strikes the ink ribbon which strikes the paper leaving a mark. Typewriters are very useful because one can write about one hundred words per minute, and even more if a skilled typer. By hand one can only write about thirty words per minute. Because of that extra time, one can send more letters and still have time to do other things.
The braille reading system is what blind people use so they can read. The braille reading system uses six dots to make all the letters of the alphabet uppercase and lowercase, numbers, punctuation marks, and a few simple words like: the, with, and of. The braille reading system is really useful because the blind can read, so they can have better jobs. Before, they could not have good jobs because they were uneducated.
The sewing machine is a machine that sews. It sews a lot faster than it can be done by hand. The sewing machine also can have a lot more sturdier stitch than when it is done by hand. It helps make life easier because it sews so quickly that when one is sewing clothing it may only take a couple of hours versus a couple of days.
So to wrap it up, I explained and summarized how four popular inventions changed the course of history.
(P.S. sorry I posted them out of order)