La aktoro aŭdas sian propran voĉon.

La means the.

So la aktoro = the actor.

Esperanto uses la when you are talking about a specific person or thing. If you said just aktoro, that would mean an actor or actor in a more general sense, depending on context.

The ending -o marks a noun in Esperanto.

So:

• aktoro = actor
• voĉo = voice

This is one of the most important patterns in Esperanto: nouns normally end in -o.

The ending -as shows present tense.

So aŭdas means hears or is hearing.

Some common verb endings are:

• -as = present
• -is = past
• -os = future
• -us = conditional
• -u = command / wish
• -i = infinitive

So from the verb aŭdi (to hear), we get:

• aŭdas = hears
• aŭdis = heard
• aŭdos = will hear

The aŭ is a diphthong, roughly like ow in English cow, though pronunciation may vary a little by accent.

So aŭdas is approximately:

• OW-dahs

Also remember that Esperanto stress usually falls on the second-to-last syllable:

• aŭ-das

This is one of the most important grammar points here.

Sia is the reflexive possessive adjective. It means his/her/their own, but specifically when it refers back to the subject of the sentence.

In La aktoro aŭdas sian propran voĉon, the subject is la aktoro. The voice belongs to that same actor, so Esperanto uses sian.

So this means:

• The actor hears his own voice.

If you used lian, it would normally mean the voice belongs to some other male person, not the actor himself.

Compare:

• La aktoro aŭdas sian voĉon = The actor hears his own voice.
• La aktoro aŭdas lian voĉon = The actor hears his voice, meaning another man's voice.

Sia means one's own and refers back to the subject of the clause.

It changes form like other adjectives:

• sia voĉo = his/her own voice
• sian voĉon = his/her own voice as a direct object
• siaj libroj = his/her own books
• sian libron = his/her own book

It does not show gender by itself. The context tells you whose thing it is.

Because adjectives agree with the noun they describe.

Here, voĉon is the direct object, so it takes -n. Any adjectives attached to it must also take -n.

So:

• voĉon = voice as direct object
• sian = agrees with voĉon
• propran = also agrees with voĉon

That is why all three match:

• sian propran voĉon

This agreement is very regular in Esperanto.

The ending -n marks the direct object.

The direct object is the thing directly affected by the verb. In this sentence, what does the actor hear? His own voice.

So:

• La aktoro = subject
• aŭdas = verb
• sian propran voĉon = direct object

Because voĉo is the direct object, it becomes voĉon.

Sian voĉon already means his own voice because sian is reflexive.

Adding propran makes it more emphatic:

• sian voĉon = his own voice
• sian propran voĉon = his very own voice / his own voice himself

So propran strengthens the idea that it is specifically the actor's own voice, not someone else's.

In many contexts, sian alone is enough, but propran adds emphasis or clarity.

Propran comes from propra, which means own, proper, or particular to someone/something.

In this sentence it reinforces possession:

• sia propra voĉo = one's own voice

Because it describes voĉon, it takes the same grammatical ending:

• propra voĉo
• propran voĉon

Yes, Esperanto word order is fairly flexible because the -n ending helps show what is the object.

The most neutral order is:

• La aktoro aŭdas sian propran voĉon.

But other orders are possible for emphasis, such as:

• Sian propran voĉon aŭdas la aktoro.

This still means the same thing, because voĉon has -n, marking it as the object.

That said, the original order is the most straightforward for learners.

Usually yes. Aŭdi means to hear in the basic sensory sense.

So:

• Mi aŭdas muzikon. = I hear music.
• Ŝi aŭdas bruon. = She hears a noise.

It is different from aŭskulti, which means to listen.

Compare:

• Mi aŭdas lin. = I hear him.
• Mi aŭskultas lin. = I am listening to him.

So in your sentence, the actor is perceiving the sound of his own voice, not necessarily deliberately listening to it.

It can use one, but Esperanto makes an important distinction:

• lia = his, belonging to some male person
• sia = his/her/their own, referring back to the subject

English often uses his for both meanings, which can be ambiguous. Esperanto is clearer.

For example, English The actor hears his voice could mean:

1. the actor hears his own voice, or
2. the actor hears another man's voice

Esperanto separates these:

• La aktoro aŭdas sian voĉon. = his own voice
• La aktoro aŭdas lian voĉon. = another man's voice

It refers to the subject of its own clause.

That matters in more complex sentences.

For a simple sentence like this one, the subject is just la aktoro, so sian clearly refers to the actor.

In longer sentences, learners need to check which clause they are in. But for this sentence, the rule is simple: sian points back to la aktoro.

Here is the breakdown:

• La = the
• aktoro = actor
• aŭdas = hears
• sian = his/her own
• propran = own, particular, emphatic own
• voĉon = voice, as direct object

So structurally:

• La aktoro = subject
• aŭdas = verb
• sian propran voĉon = object phrase

This is a very typical Esperanto sentence pattern: subject + verb + object.