The words allowed and aloud sound similar when spoken, but are different words.
The word allowed is a verb (its adjective is allowable).
Meanings: permissible; acceptable.
The word aloud is an adverb.
Meanings: loudly; noisily; audibly; distinctly.
Antonym: silently; quietly.
Examples of allowed:
1. The hostel warden allowed the students to have a late-night party on Christmas Eve.
2. Do you think children below eighteen years should be allowed to watch films with a U/A certificate?
3. Visitors are not allowed in the hospital after 7p.m.
Examples of aloud:
1. The child cried aloud in her sleep, apparently in the midst of a nightmare.
2. The spectators were screaming aloud in excitement as Sachin neared his double century.
3. The carpenter shouted aloud in pain on mistakenly hitting his finger with the hammer.