El acúfeno es un zumbido percibido.

In Spanish, a definite article is often used when giving a general definition:

El acúfeno es... = Tinnitus is...

This is very natural in Spanish. English often leaves the article out in definitions, but Spanish commonly keeps it.

Without el, Acúfeno es... would sound unnatural here.

Acúfeno is the medical or formal word for tinnitus.

In everyday speech, many people may use more descriptive phrases instead, such as:

• pitido en el oído
• zumbido en los oídos

So acúfeno is correct, but it sounds a bit technical or medical.

Es is used because the sentence is giving a definition or describing what something is by nature:

• El acúfeno es un zumbido percibido.

Spanish uses ser for definitions, identity, and essential description.

Estar would suggest a temporary state or condition, which does not fit here.

Zumbido means buzzing, humming, or sometimes ringing, depending on context.

It is a masculine noun, so it takes:

• un zumbido
• el zumbido

Its gender is something you simply learn with the word. There is no special rule here that would make it obvious to an English speaker.

Percibido adds the idea that the buzzing is perceived or heard/felt by the person.

So:

• un zumbido = a buzzing
• un zumbido percibido = a perceived buzzing

This sounds formal and precise, which fits a medical-style definition.

Percibido is the past participle of percibir (to perceive), but here it is being used like an adjective.

It describes zumbido, so it must agree with it in gender and number:

• un zumbido percibido — masculine singular
• una sensación percibida — feminine singular
• sonidos percibidos — masculine plural

So in this sentence, percibido is functioning adjectivally.

In Spanish, adjectives often come after the noun, especially when they are:

• descriptive
• technical
• classifying

So zumbido percibido is the normal order.

Putting it before the noun — percibido zumbido — would sound unnatural here.

It agrees with zumbido, not acúfeno.

Structure:

• El acúfeno = subject
• es = verb
• un zumbido percibido = predicate noun phrase

Inside that phrase, percibido modifies zumbido, so both are masculine singular.

It is pronounced roughly like:

a-KOO-fe-no

The written accent in acúfeno shows that the stress falls on the ú syllable:

• a-cú-fe-no

Without the accent mark, Spanish pronunciation rules would suggest a different stress pattern, so the accent is necessary.

Yes. That would be grammatically correct and a bit more transparent for learners:

• El acúfeno es un zumbido que se percibe.

This means essentially the same thing as un zumbido percibido.

The version with percibido is:

• more concise
• more formal
• more technical in tone

The version with que se percibe may feel easier to understand if you are still learning participles.

It is grammatical and understandable, but it sounds formal and somewhat medical.

In everyday language, people might say something more like:

• El acúfeno es un pitido en el oído.
• El acúfeno es como un zumbido que oyes.

So the original sentence is fine, but it sounds more like a definition in a medical text than casual conversation.

The plural would be:

• Los acúfenos son zumbidos percibidos.

Changes:

• El → Los
• acúfeno → acúfenos
• es → son
• un zumbido → zumbidos
• percibido → percibidos

Everything agrees in number, just as you would expect in Spanish.