Medimos el umbral auditivo en decibeles.

Medimos is the nosotros form of medir, which means to measure.

In this sentence, it most naturally means we measure.

A useful detail: medimos can also mean we measured in the preterite, because the nosotros form looks the same in the present and simple past for many -ir verbs. So context tells you which one is meant. In a general or technical statement like this, the present-tense meaning we measure is the most likely.

Spanish often leaves out subject pronouns because the verb ending already tells you who the subject is.

So:

• Medimos = we measure
• Nosotros medimos = also we measure, but with extra emphasis or contrast

If you add nosotros, it can sound like:

• We measure it, as opposed to someone else
• or it can simply be more explicit

Without nosotros, the sentence sounds natural and normal.

El means the, and here it refers to a specific concept: the hearing threshold.

In technical or scientific language, Spanish often uses the definite article with established concepts and measurements. So el umbral auditivo sounds like a recognized thing being measured, not just any random threshold.

• el umbral auditivo = the hearing threshold
• un umbral auditivo = a hearing threshold

The version with el is the more natural choice here.

In Spanish, descriptive adjectives usually come after the noun.

So:

• umbral auditivo
• literally: threshold auditory
• naturally: auditory threshold or hearing threshold

This noun + adjective order is very common in Spanish, especially in technical vocabulary.

Auditivo means auditory or related to hearing.

So umbral auditivo is a technical term meaning something like:

• auditory threshold
• hearing threshold

In natural English, hearing threshold is often the smoother translation, even though auditivo more literally matches auditory.

Spanish uses en to show the unit in which something is measured.

So:

• en decibeles = in decibels
• en metros = in meters
• en segundos = in seconds

Here, en tells you the scale or unit used for the measurement.

Because decibeles is being used as a unit of measurement, not as a specific set of objects.

So Spanish says:

• en decibeles
• en metros
• en grados

not normally:

• en los decibeles

Using no article is the standard way to say in decibels.

Yes. Decibeles is very common in Latin America and is fully correct.

You may also see decibelios, which is also correct and is often more common in Spain.

So both are valid:

• decibeles
• decibelios

For Latin American Spanish, decibeles is especially natural.

Yes. Medir is irregular.

In the present tense, it changes from e to i in most forms:

• yo mido
• tú mides
• él/ella mide
• nosotros medimos
• ellos miden

Notice that nosotros does not change the stem, so it stays medimos, not midimos.

That pattern is common with stem-changing verbs: the nosotros form often keeps the original stem.

Yes. This is an important point.

Medimos can mean either:

• we measure (present)
• we measured (preterite)

The form is identical. You tell the difference from context.

For example:

• Hoy medimos el umbral auditivo.
  This could mean Today we measure the hearing threshold or, in the right context, Today we measured the hearing threshold.

In a standalone technical statement like Medimos el umbral auditivo en decibeles, the default interpretation is usually present: We measure the hearing threshold in decibels.

Because el umbral auditivo is a thing or concept, not a person.

The personal a is mainly used before specific human direct objects, and sometimes pets or personified beings.

Compare:

• Vemos al doctor. = We see the doctor.
• Medimos el umbral auditivo. = We measure the hearing threshold.

Since umbral auditivo is not a person, there is no a.

Yes. Umbral de audición is also a natural and correct way to express this idea.

So these are both possible:

• umbral auditivo
• umbral de audición

They are very close in meaning. In technical writing, choice may depend on field, style, or regional preference. Umbral auditivo sounds concise and technical; umbral de audición can sound a bit more transparent to learners because it literally includes hearing.

A rough pronunciation guide is:

• Medimos = meh-DEE-mos
• el = ehl
• umbral = oom-BRAL
• auditivo = ow-dee-TEE-vo
• en = ehn
• decibeles = deh-see-BEH-les

A few helpful pronunciation notes:

• Spanish vowels are usually short and clear
• r in umbral is a light tap here
• the stress falls on:
  • di in medimos
  • bral in umbral
  • ti in auditivo
  • be in decibeles