Hørselstapet er tydelig.

Because Norwegian usually writes compound nouns as a single word.

So:

• hørsel = hearing
• tap = loss
• hørselstap = hearing loss

Then -et is added to make it definite:

• hørselstap = hearing loss
• hørselstapet = the hearing loss

This is very normal in Norwegian. English often uses two words where Norwegian uses one compound.

-et is the definite ending for a neuter noun in the singular.

So instead of putting a separate word for the in front, Norwegian usually adds the definiteness to the end of the noun:

• et hørselstap = a hearing loss
• hørselstapet = the hearing loss

That is why there is no separate word for the in the sentence.

It is a neuter noun in Bokmål.

Its basic forms are:

• et hørselstap = a hearing loss
• hørselstapet = the hearing loss
• hørselstap / hørselstapene = hearing losses / the hearing losses

Knowing that it is neuter helps you choose the right article and endings.

Er is the present tense of å være, which means to be.

So:

• er = is / are / am, depending on context

In this sentence, Hørselstapet er tydelig, it simply means The hearing loss is clear/obvious.

Norwegian uses the same form er for all persons:

• jeg er
• du er
• han/hun er
• vi er

That is much simpler than English.

Because tydelig is an adjective ending in -ig, and adjectives of this type usually do not add -t in the neuter singular.

So even though hørselstapet is neuter, the adjective stays:

• et tydelig tegn
• tegnet er tydelig
• hørselstapet er tydelig

But in plural or certain other forms, you can get:

• tydelige tegn
• tegnene er tydelige

So the form tydelig here is completely normal.

Because the definiteness is already built into the noun.

In English, you say:

• the hearing loss

In Norwegian, you usually say:

• hørselstapet

So the is not a separate word here; it is expressed by the ending -et.

The difference is mainly indefinite vs definite:

• hørselstap = hearing loss / a hearing loss
• hørselstapet = the hearing loss

So:

• Hørselstap er vanlig hos eldre. = Hearing loss is common among older people.
  
  • This is more general.
• Hørselstapet er tydelig. = The hearing loss is obvious.
  
  • This refers to a specific case already known from the context.

A rough guide is:

• Hørselstapet: stress the first syllable: HØR-sel-sta-pet
• er: a short ehr sound
• tydelig: roughly TY-de-lig

A few pronunciation notes:

• ø in hør- does not exist in standard English. It is somewhat like the vowel in British bird, but with rounded lips.
• y in tydelig is also not an English vowel. Say ee while rounding your lips.
• In natural speech, endings can sound lighter than they look in writing.

If you want to sound natural, put the main stress on HØR in hørselstapet.

Yes. It is the standard pattern:

• Subject + verb + adjective

So:

• Hørselstapet = subject
• er = verb
• tydelig = predicative adjective

This is the most natural and neutral way to say it.

A more unusual order like Tydelig er hørselstapet would sound literary, marked, or unnatural in ordinary speech.

Yes, Hørselstapet er tydelig is standard Bokmål.

In Nynorsk, you might more naturally see:

• Høyrselstapet er tydeleg.

So the sentence is perfectly correct Norwegian, but the spelling reflects Bokmål.