I noticed there are
e in the following sentence.
représentent des sons (represent sounds)
Can I use
e in place of
There are many accents in French, you can't decide to use them or not as it pleases you.
It's always here for a reason, and if you don't use it when needed, either the word doesn't mean anything, or it means something else. Most of the time they change the pronunciation, too.
For example, for many verbs, the past participle ends with é:
to buy / I buy / I've bought = acheter / j'achète / j'ai acheté
As you can see, achète and acheté don't have the same use (and don't pronounce the same way).
Some examples to show you accents are VERY common:
une forêt = a forest
une mère, un père, un frère = a mother, a father, a brother
un pré = a field
Noël = Christmas
s'il te plaît = please
cocaïne = cocaine
sûr = sure / safe BUT sur = on / over
à = to / in BUT (il) a = (he) has
un hôpital = a hospital
où = where BUT ou = or
For many words, you have to learn them as they are, the pronunciation often helps, and there are rules too.
Bonus: créée (= created, feminine past participle of the verb créer = to create).
This is an accent called acute. é is therefore called "e acute". The prononciation is different from e and cannot be dropped in any case unless an alternative spelling exists (like clef and clé).
The answer to your question on the presence of
é is simply that this is how the word should be spelled.
This character is a "e accent aigu", you pronounce it like the "e" in "heya". Writing the words with a simple "e" instead is a mistake. You can do that only when:
The "é" is a capital letter (though you could use the capital "É", a simple "E" is easier to write). In this case, be aware of the possible ambiguities.
You are writing something using the ASCII format ("é" isn't part of ASCII so you don't have a choice)
Some words have very different meanings if you forget the accent: for example "tombé" means "fallen" whereas "tombe" means "grave"
Not seeing the "real" reason: these accents replace the letter s - "école" - very similar to "school" in English, for example. Or "forêt" (as above) is similar to "forest" - French evolved from Latin, after all, and in that evolution the writing changed a bit, and the s became the accent mark. It helps the reader to figure out pronunciation as well, because those silent s impact the way the word is pronounced (roughly). So basically, it's part of the proper/correct spelling of these words. And that means they're not the same letter, really. They're more like digraphs. French considers them to be, but Spanish, for example, considers n and nn to be different letters.
The bare letter «e» is pronounced /ǝ/ (or dropped) unless there's something about its context to make it /e/ (like «é»; as in cachet) or /ɛ/ (like «è»; as in bel) or /ɑ̃/ (as in content) or /ɛ̃/ (as in bien). Any diacritic makes it a full vowel, never a schwa.
The goal of the e accent aigu (é) is to distinguish the phoneme /e/ from the phoneme /ə/. In the example phrase, représentent is thus pronounced /ʁǝpʁezɑ̃/. This is no different in principle from how represent is pronounced as /rɛprɪzɛnt/ in English.
NB The circumflex, such as in forêt, is used to indicate an s that used to be pronounced. I chose this example because the English word forest makes this easy to see. In principle you could therefore leave out the circumflexes for pronunciation purposes, but many are still kept to prevent homonymy in writing. That being said, I'd strongly advise against leaving out or replacing any accents in practice.