Learn Portuguese (Portugal): A máquina de lavar roupa faz barulho.

In Portuguese, appliances and tools are often named by describing what they do. It literally means 'machine of to wash clothing'. You use de plus the infinitive verb (lavar) and the object (roupa) to show its purpose. Another common example is máquina de secar roupa (tumble dryer).

Why is 'roupa' singular here if the English translation says 'clothes'?

In Portuguese, roupa is typically used as a singular collective noun to mean 'clothing', 'apparel', or 'laundry'. While the plural roupas exists (usually for specific garments), the singular roupa is the standard way to talk about laundry in general.

Which verb does 'faz' come from, and is it always used for noise?

It is the 'ele/ela' form of the irregular verb fazer (to do / to make). Just like in English, Portuguese uses the verb 'to make' when talking about producing sounds, so 'makes noise' translates directly to faz barulho.

Why isn't there an article like 'um' before 'barulho'?

Because we are talking about noise in a general, uncountable sense, no article is needed. If you said faz um barulho, it would imply the machine makes one specific, strange noise (like a clank or a squeak), rather than just generally being loud.