En el supuesto de que pare el ruido, retomaremos.

En el supuesto de que means something like on the assumption that, assuming that, or in the event that.

It is grammatically correct, but it sounds formal and somewhat written. In everyday Latin American Spanish, people would more often say:

• Si para el ruido, retomaremos.
• En caso de que pare el ruido, retomaremos.
• Cuando pare el ruido, retomaremos. (if the speaker expects it to stop)

So yes, it is valid, but it is not the most casual way to say it.

Because this clause requires the subjunctive.

• pare = present subjunctive of parar
• para = present indicative of parar

After expressions like en el supuesto de que, Spanish uses the subjunctive because the situation is hypothetical, assumed, or not yet confirmed.

So:

• En el supuesto de que pare el ruido... = correct
• En el supuesto de que para el ruido... = not standard here

It triggers the subjunctive because it introduces something that is uncertain, imagined, or conditional rather than presented as a fact.

Spanish often uses the subjunctive after expressions that involve:

• doubt
• possibility
• emotion
• purpose
• conditions that are not yet real

Here, the speaker is not saying the noise has stopped. They are saying: assuming it stops. Since that event is only a possibility, Spanish uses the subjunctive: pare.

The subject is el ruido.

So the clause literally works like this:

• pare = stops
• el ruido = the noise

That means el ruido is the thing doing the action of stopping.

In more neutral word order, you could also say:

• En el supuesto de que el ruido pare, retomaremos.

That sounds a little more straightforward to many learners. Both versions are possible.

Spanish allows more flexible word order than English.

Both of these are possible:

• ...de que pare el ruido
• ...de que el ruido pare

Putting the verb before the subject can sound a bit more natural in some contexts, especially in subordinate clauses. It does not change the basic meaning.

For a learner, it may help to think of both as meaning:

• ...that the noise stop

Retomaremos is the future tense of retomar, meaning we will resume, we will pick back up, or we will continue again after an interruption.

So:

• retomar = to resume / take up again
• retomaremos = we will resume

In context, it suggests that something was interrupted because of the noise, and once that problem is gone, we will resume.

It is natural, especially in formal or professional contexts. But there are other common options depending on tone:

• retomaremos = we will resume / pick back up
• continuaremos = we will continue
• seguiremos = we will keep going
• reanudaremos = we will resume (more formal)

For example:

• Si para el ruido, continuaremos.
• Si para el ruido, seguimos. (more conversational in some contexts)
• En cuanto pare el ruido, reanudaremos la reunión.

So retomaremos is perfectly good, especially if the idea is starting again after a pause.

Yes. The sentence sounds fairly formal, especially because of en el supuesto de que and retomaremos.

It could fit contexts like:

• a meeting
• a lecture
• an official announcement
• a written report
• a formal conversation

A more everyday version might be:

• Si para el ruido, seguimos.
• Cuando pare el ruido, continuamos.
• En cuanto pare el ruido, retomamos.

So the original sentence is correct, but it does not sound especially casual.

Yes, very often.

A simpler version would be:

• Si para el ruido, retomaremos.

That is much more common in everyday speech.

However, there is a slight nuance:

• si = plain if
• en el supuesto de que = assuming that, under the assumption that

So the original sounds more formal and slightly more abstract or careful.

Yes, and that would be very natural.

• En caso de que pare el ruido, retomaremos.

This is still somewhat formal, but usually more common and more natural than en el supuesto de que.

Like the original expression, en caso de que also requires the subjunctive:

• pare, not para

Because the sentence begins with a subordinate clause:

• En el supuesto de que pare el ruido

Then the main clause comes after it:

• retomaremos

In Spanish, when a clause like this comes first, it is normal to separate it from the main clause with a comma.

So the comma helps show the structure:

• [conditional/hypothetical clause], [main clause]

Yes, depending on context.

Spanish often uses the present to talk about a near or planned future:

• En el supuesto de que pare el ruido, retomamos.

That can sound more immediate or conversational.

But retomaremos is also correct and sounds a bit more explicit and formal about the future.

So both can work:

• retomaremos = more clearly future, often more formal
• retomamos = also possible, often more immediate or conversational

Not exactly the same, though they may be close in context.

• En el supuesto de que pare el ruido = assuming the noise stops / if the noise stops
• Cuando pare el ruido = when the noise stops

Cuando often suggests the speaker expects that event to happen, while en el supuesto de que presents it more as a condition or assumption.

So:

• cuando = more expectation
• en el supuesto de que = more hypothetical/formal

Yes, parar is common and acceptable here. Spanish often uses parar with things like noise, rain, engines, traffic, and other processes or disturbances.

You might also hear:

• que cese el ruido = that the noise cease (more formal)
• que se acabe el ruido = that the noise end
• que deje de haber ruido = that there stop being noise

But pare el ruido is perfectly understandable and natural enough, especially in neutral or formal contexts.