يأخذ الزائر خريطة المتحف بالإضافة إلى الدليل الصوتي.

Because Arabic often uses verb–subject–object order, especially in Modern Standard Arabic.

So:

• يأخذ الزائر... = literally takes the visitor...
• Natural English reverses that to the visitor takes...

You could also say:

• الزائر يأخذ خريطة المتحف...

That is also correct, but it puts more emphasis on the visitor.

يأخذ is the 3rd person masculine singular imperfect form of the verb أخذ.

Here it means:

• he takes
• or, depending on context, he is taking

Since الزائر is a singular masculine noun, يأخذ matches it.

In this sentence, it is best understood as a simple present: the visitor takes.

Because the verb comes from the root verb أخذ (to take), and the hamza is part of the word.

The basic pair is:

• أخذَ = he took
• يأخذُ = he takes / he is taking

So the hamza does not disappear in the imperfect form; it stays in the spelling:

• يأخذ

A rough pronunciation is yaʾkhudh(u).

الزائر means the visitor.

A few useful details:

• زائر by itself means visitor
• الزائر means the visitor
• It comes from the verb زار = to visit

So زائر is literally something like one who visits.

This is an iḍāfa construction, often called a genitive/possessive construction.

It means:

• خريطة المتحف = the museum map
• literally: map of the museum

Important things to notice:

• The first noun is خريطة = map
• The second noun is المتحف = the museum
• In an iḍāfa, the first noun usually does not take ال
• The whole phrase becomes definite because the second noun is definite

So:

• خريطة متحف = a museum map / a map of a museum
• خريطة المتحف = the museum map / the map of the museum

Because in Arabic, adjectives come after the noun they describe.

So:

• الدليل = the guide
• الصوتي = the audio / auditory

Together:

• الدليل الصوتي = the audio guide

Also, Arabic adjectives must agree with the noun in:

• definiteness
• gender
• number
• case

Since الدليل is definite, the adjective must also be definite:

• الدليل الصوتي = the audio guide
• compare with دليل صوتي = an audio guide

بالإضافة إلى is a fixed expression meaning:

• in addition to
• besides
• as well as

So here it introduces an extra item:

• خريطة المتحف بالإضافة إلى الدليل الصوتي
• the museum map in addition to the audio guide

This expression is common in formal Arabic and written MSA.

Because بالإضافة إلى already does the job of linking them.

Compare:

• خريطة المتحف والدليل الصوتي = the museum map and the audio guide
• خريطة المتحف بالإضافة إلى الدليل الصوتي = the museum map in addition to the audio guide / as well as the audio guide

So و would just mean and, while بالإضافة إلى adds the meaning of in addition to.

A fully vocalized version would be:

يَأْخُذُ الزَّائِرُ خَرِيطَةَ الْمَتْحَفِ بِالإِضَافَةِ إِلَى الدَّلِيلِ الصَّوْتِيِّ

Here is why:

• يَأْخُذُ: indicative imperfect verb
• الزَّائِرُ: nominative, because it is the subject
• خَرِيطَةَ: accusative, because it is the direct object
• الْمَتْحَفِ: genitive, because it is the second term of the iḍāfa
• بِالإِضَافَةِ: genitive after the preposition بِ
• إِلَى الدَّلِيلِ: الدليلِ is genitive after إلى
• الصَّوْتِيِّ: genitive because it is an adjective describing الدليلِ

In normal Arabic writing, these endings are usually not written, but they are still understood grammatically.

The ال is written the same way each time, but its pronunciation changes with sun letters.

In this sentence:

• الزائر is pronounced roughly az-zāʾir
• الدليل is pronounced roughly ad-dalīl
• الصوتي is pronounced roughly aṣ-ṣawtiyy

That happens because ز, د, and ص are sun letters, so the l sound of ال is assimilated to the next consonant.

It is still written as:

• الزائر
• الدليل
• الصوتي

but pronounced with that assimilation.