Ses perdesi entonasyon için tekrar kontrol edildi.

Ses perdesi is a noun compound in Turkish.

• ses = sound / voice
• perde = curtain, but in some fixed expressions it can refer to a pitch level or register
• perdesi has the compound ending -(s)I

In Turkish, when one noun modifies another noun, the second noun often takes this ending:

• okul kapısı = school door
• mutfak masası = kitchen table
• ses perdesi = pitch / vocal pitch

So perdesi does not mean his/her curtain here. It is just the normal form of the second noun in this kind of compound.

Because ses perdesi and sesin perdesi are not exactly the same structure.

• ses perdesi = a lexicalized noun compound, basically a set term
• sesin perdesi = a true possessive phrase, literally the pitch/curtain of the sound/voice

For many learners, this is an important distinction:

• Noun compound: ses perdesi
• Genitive + possessive: sesin perdesi

In practice, ses perdesi is the normal dictionary-style expression for pitch in this context.
So the sentence uses the standard compound, not a more literal possessive construction.

İçin is a postposition meaning for.

So:

• entonasyon için = for intonation

A useful thing to notice is that Turkish uses postpositions, so they come after the noun, unlike English prepositions:

• English: for intonation
• Turkish: entonasyon için

This phrase expresses purpose or intended use here: the pitch was checked again for intonation purposes.

Because kontrol etmek is a very common Turkish compound verb.

• kontrol = control / check / inspection
• etmek = to do

Together:

• kontrol etmek = to check / to inspect

In the sentence, the form is passive and past:

• kontrol edildi = was checked

This same pattern is very common in Turkish, especially with borrowed nouns:

• analiz etmek = to analyze
• takip etmek = to follow / track
• kontrol etmek = to check

So kontrol edildi is not strange or exceptional; it is a very normal Turkish verb phrase.

Edildi is the passive past form of etmek in this kind of compound verb.

You can think of it like this:

• etmek = to do
• edilmek = to be done
• kontrol edildi = it was checked

In this sentence, the important point is the passive meaning:

• active: Birisi ses perdesini kontrol etti. = Someone checked the pitch.
• passive: Ses perdesi kontrol edildi. = The pitch was checked.

Turkish often uses the passive when the doer is unknown, unimportant, or simply not mentioned.

Yes. In this sentence, ses perdesi is the grammatical subject.

Because the verb is passive:

• Ses perdesi ... kontrol edildi. = The pitch ... was checked.

If you make it active, the structure changes:

• Birisi ses perdesini entonasyon için tekrar kontrol etti.
• Here ses perdesini is the object, marked with the accusative -i.

So one useful contrast is:

• passive subject: ses perdesi
• active object: ses perdesini

That change is very typical in Turkish passives.

Tekrar means again.

Here it tells you that the checking happened one more time:

• tekrar kontrol edildi = was checked again

Its position is fairly natural here, right before the verb phrase. Turkish word order is flexible, so tekrar can sometimes move, but different placements can shift emphasis a little.

This sentence sounds natural because the structure is:

• Ses perdesi — topic/subject
• entonasyon için — purpose
• tekrar — adverb
• kontrol edildi — verb

You may also see yeniden used for again/anew, but tekrar is very common in everyday Turkish.

Because Turkish normally prefers verb-final word order.

A very common Turkish pattern is:

• subject + other information + verb

So in this sentence:

• Ses perdesi = subject/topic
• entonasyon için = purpose phrase
• tekrar = adverb
• kontrol edildi = verb

That makes the sentence feel very natural in Turkish.
English often puts the verb earlier, but Turkish typically saves it for the end.

Yes. Entonasyon is a normal Turkish word, even though it is a loanword.

Turkish uses many borrowed terms, especially in technical, musical, linguistic, and academic contexts. So a sentence like this can mix:

• a native Turkish word: ses
• a Turkish compound expression: ses perdesi
• a loanword: entonasyon
• a common compound verb: kontrol etmek

That is completely normal in modern Turkish.

Because Turkish does not have articles like English the and a/an.

So Turkish often leaves definiteness to context.

• Ses perdesi kontrol edildi. can naturally mean The pitch was checked.
• The context tells you which pitch is meant.

English requires an article, but Turkish does not.
That is why the Turkish sentence can be perfectly complete without a separate word for the.