Some museum provides cellphone application with a digital audio guide, when we click a certain collection, there is introduction of that objects. How to address the person who read the text? He or she is not actually an interpreter since he or she just read out what is provided by the museum curator. Maybe a dubber?
Such a museum guide, virtual or not, is normally referred to as a docent:
docent, n.: a person who is a knowledgeable guide, especially one who conducts visitors through a museum and delivers a commentary on the exhibitions.
Update: a studio offering training for such artists refers to them thusly:
One of the most overlooked yet fertile career tracks for voice artists is the audio tour.
Audio tour voice over narrators are specialists in vocal inflection, timing and pacing – and they are highly sought after by producers and directors.
The person reading the text, while reading it, would typically be called the narrator (this is how Audible refer to them, for example).
Other, less specific terms include artist or performer.
In general you can use a variety of terms for the person or profession. Someone who also or usually performs more serious “dramatic” recording work might be a voice actor¹ or, in non-dramatic rôles, a voice-over artist:
From Oxford Living Dictionaries:
A person whose job is to provide the voices for characters in animated films, dubbed foreign language films, audio dramas, etc.
‘when I arrived in Hollywood in after drama school, I hoped to find work as a voice actor’
A piece of narration in a film or broadcast, not accompanied by an image of the speaker.
‘the budget is summarized in a voice-over at the end of the news’
[mass noun] ‘the coordination of live voice-over, music, and slides’
[as modifier] ‘voice-over dialogue’
Narrate (spoken material) for a film or broadcast as a voice-over.
‘we had to voice-over some passages of dialogue’
‘the commercials are voice-overed’
¹ This is very likely not the answer you want unless that is their vocation, and they happen to be “performing” audio books as their regular job.