La retransmisión llega a cada oyente.

Because llegar can mean not only to arrive, but also to reach someone or something. In that use, Spanish often introduces the person affected with a:

• La carta llegó a María. = The letter reached María.
• La señal llega a todo el edificio. = The signal reaches the whole building.

So La retransmisión llega a cada oyente means the broadcast reaches each listener.

Because cada is followed by a singular noun in Spanish.

So you say:

• cada oyente = each listener
• cada día = each day
• cada persona = each person

This is different from English, where learners sometimes expect a plural idea because the meaning refers to many people. Grammatically, though, Spanish keeps the noun singular after cada.

Here llega means reaches rather than arrives.

The basic meaning of llegar is to arrive, but it is also used for things like signals, news, sound, messages, broadcasts, or effects that reach a person or place.

So in this sentence, the idea is not that the broadcast is physically arriving somewhere like a person would. It means the transmission gets through to each listener.

Spanish often uses the definite article more than English does. Here la retransmisión refers to a specific broadcast or relay that is already understood from context.

So:

• La retransmisión llega a cada oyente = the broadcast / the relay reaches each listener

Without the article, the sentence would sound less natural in most normal contexts. Spanish usually prefers the article when talking about a specific event, thing, or known item.

Transmisión is the more general word for transmission or broadcast.

Retransmisión usually suggests a relay, rebroadcast, or a transmission that is being passed on from one source to others. In Spain, it is commonly used for radio, TV, sports coverage, or live event relays.

So retransmisión is a bit more specific than transmisión.

Oyente is a common-gender noun. That means the word form stays the same, and the gender is shown by other words if needed:

• el oyente = the male listener
• la oyente = the female listener

In cada oyente, there is no article showing gender, so it can refer to listeners of any gender. In other words, oyente here is gender-neutral in practice.

They are similar, but not exactly the same.

• a cada oyente = to each listener, one by one
• a todos los oyentes = to all the listeners, as a group

Cada emphasizes the individual members of the group.
Todos los emphasizes the whole group together.

So the original sentence has a slightly more individual feel: the broadcast reaches every single listener.

Yes, absolutely. That is a very natural alternative.

Spanish often uses an indirect object pronoun like le together with the full phrase:

• A cada oyente le llega la retransmisión.

This structure is especially common when the indirect object comes first. It gives a bit more emphasis to a cada oyente.

So both are possible:

• La retransmisión llega a cada oyente.
• A cada oyente le llega la retransmisión.

The meaning is essentially the same.

The present tense here expresses a general or current fact:

• the broadcast reaches each listener
• the transmission gets through to each listener

Spanish uses the present tense very often for:

• general truths
• descriptions
• what is happening now
• commentary or narration

So llega is the normal tense here.

Retransmisión is stressed on the last syllable: re-trans-mi-SIÓN.

It has a written accent because words ending in -n are normally stressed on the second-to-last syllable in Spanish. Since this word is stressed on the last syllable instead, it needs the accent mark.

By contrast, oyente is stressed normally on the second-to-last syllable: o-YEN-te, so it does not need an accent mark.