Where to put the periods: full parenthetical sentence at end of sentence? [duplicate]

I have two complete sentences; the second is in parentheses, essentially a comment on the first. Where do I place the periods? I would use this:

They played opera. (I covered my ears.)

Is this punctuation correct?

Punctuation within parentheses

If your parentheses enclose a sentence-within-a-sentence, don't use a period within the parentheses. Do, however, use a question mark or an exclamation point if it is called for.

Mother love (hers was fierce) ruined the young boy's life.

They finally said (why couldn't they have admitted it earlier?) that she had been there.

The wedding reception (what a fiasco!) ended abruptly.

If the parentheses enclose a complete sentence that stands alone, keep the period within the parentheses.

(Her father was the only one who didn't attend.)

From Cliffsnotes

The punctuation marks are correct.
When a full sentence is placed between parentheses, the period is placed inside them too. For the sentences surrounding the parenthetical one, the rule is the usual one.