El auricular izquierdo no funciona, así que uso el altavoz.

Auricular is a masculine noun here, so it takes el: el auricular.

A few useful notes:

• In this sentence, auricular means earpiece, earbud, or headphone piece, depending on context.
• Even though auricular can also be an adjective in other contexts, here it is being used as a noun.
• Since it is masculine singular, the adjective also matches it: izquierdo.

So:

• el auricular izquierdo
• los auriculares izquierdos

Here, auricular refers to an earpiece / earbud / headphone side.

Depending on the situation, a learner might hear different English translations:

• earbud
• headphone
• earpiece

In Latin America, people may also use other words depending on the country, such as:

• audífono(s)
• auriculares
• sometimes other regional terms

In this sentence, el auricular izquierdo means the left earbud/headphone side.

In Spanish, descriptive adjectives usually come after the noun.

So:

• el auricular izquierdo = the left earpiece
• la mano izquierda = the left hand
• la puerta derecha = the right door

This is the normal word order in Spanish. Putting izquierdo before the noun would sound unusual here.

No funciona means it doesn’t work / it isn’t working, and it is a very common way to talk about devices.

It focuses on the fact that it is not working, without necessarily saying why.

Compare:

• No funciona = it doesn’t work
• Está roto = it is broken
• No sirve = it’s no good / it doesn’t work / it’s unusable

So no funciona is a natural, general way to describe a device that is not working properly.

Yes. Funcionar is very commonly used for machines, electronics, devices, apps, and systems.

Examples:

• Mi celular no funciona.
• La computadora funciona bien.
• El micrófono no funciona.
• El auricular izquierdo no funciona.

For an English speaker, it may help to think of funcionar as to work in the sense of to operate properly.

Así que means so, therefore, or so then.

It connects a cause and a result:

• El auricular izquierdo no funciona, así que uso el altavoz.
  • The left earpiece doesn’t work, so I use the speaker.

It is a very common connector in everyday Spanish.

Other similar connectors include:

• por eso = that’s why / for that reason
• entonces = so / then
• por lo tanto = therefore

But así que is especially natural in conversation.

The comma helps separate the two related clauses:

• El auricular izquierdo no funciona
• así que uso el altavoz

In writing, Spanish often uses a comma before connectors like así que when joining two complete ideas. It makes the sentence easier to read and sounds natural.

Even if punctuation style can vary a little, the comma here is standard and natural.

Spanish often uses the simple present where English might use either:

• I use
• I’m using

So uso el altavoz can mean:

• I use the speaker
• I’m using the speaker

The exact meaning depends on context.

In this sentence, because the first clause describes a current problem, uso el altavoz is naturally understood as I use / I’m using the speaker instead.

Spanish does have estoy usando, but the simple present is often more common than English learners expect.

Altavoz is a masculine noun, so it takes el:

• el altavoz
• los altavoces

It means speaker or loudspeaker.

A useful detail:

• the plural changes spelling: altavoz → altavoces

So:

• Uso el altavoz. = I use the speaker.
• Uso los altavoces. = I use the speakers.

Yes. Depending on the country, people may also say things like:

• parlante
• bocina
• speaker (in some informal contexts)

But altavoz is widely understood and completely correct.

So for learners:

• altavoz is a safe, standard choice
• regional alternatives may be more common in everyday speech in some places

It is singular because the sentence is talking about one side: the left earpiece.

So the idea is:

• the left one does not work
• therefore I use the speaker

If you wanted to talk about headphones in general, you might use the plural:

• Los auriculares no funcionan. = The headphones don’t work.

But here the sentence specifically singles out one part:

• El auricular izquierdo no funciona.

In many parts of Latin America, yes. Audífono is often used for earphones/headphones.

However, usage varies by region:

• in some places, audífonos commonly means headphones/earbuds
• in other contexts, audífono can also mean hearing aid

So auricular is clear and correct, but in real life you may often hear:

• El audífono izquierdo no funciona.

A learner should know both, but the most common choice depends on the country.

Yes, but there is a slight difference in feel.

• No funciona = it doesn’t work
• No sirve = it’s no good / it doesn’t work / it’s useless

For electronics, no funciona is often the most direct and neutral choice.

Examples:

• El auricular izquierdo no funciona.
• El auricular izquierdo no sirve.

Both are possible, but no funciona sounds especially natural when talking about whether a device operates correctly.