Suara langkah di lorong terdengar begitu jernih malam ini.

In Indonesian, noun–noun phrases commonly work like head + modifier.

• suara = the main noun (the “head”): sound
• langkah = the specifying noun: footsteps/steps
  So suara langkah means the sound of (a) step/footsteps. Reversing it to langkah suara would sound unnatural and would suggest “steps that are sound” rather than “sound of steps.”

langkah can mean step or footstep depending on context. In a sentence like this, it naturally refers to footsteps. Indonesian often doesn’t mark plural explicitly if it’s already understood.
If you want to emphasize multiple footsteps, you can say:

• suara langkah-langkah di lorong… (clearer “footsteps” feel)

Both can mean can be heard / sounds. Common differences:

• terdengar: often feels a bit more neutral/formal/written
• kedengaran: very common in spoken Indonesian (especially in some regions)
  In many contexts, you can swap them:
• Suara langkah di lorong kedengaran begitu jernih malam ini.

Indonesian often doesn’t need a copula like “is.” Instead, adjectives can act as predicates directly, or you use verbs like terdengar. Here, the structure is:

• Suara langkah … terdengar (sounds/is heard) begitu jernih (so clear)

begitu means so / that (degree)—often pointing to an intensity that feels noticeable in the moment.
sangat means very, more straightforward intensity.
So:

• begitu jernih = “so clear (like, surprisingly/remarkably clear)”
• sangat jernih = “very clear” (more plain)

Both can translate as “clear,” but the nuance differs:

• jernih: clear in a pure/crisp sense (often for water, air, sound: “crystal clear”)
• jelas: clear in the sense of distinct/understandable (often for speech, instructions, meaning)
  For crisp audible detail, jernih fits well.

Time expressions are flexible. Ending with malam ini is very natural. You can also front it for emphasis:

• Malam ini, suara langkah di lorong terdengar begitu jernih. Both are correct; the second highlights “tonight” as the scene-setting detail.

Yes, but the feel changes slightly:

• lorong = corridor/hallway/passageway, very common and general
• koridor = a loanword, often used in more formal contexts (buildings, offices) or technical talk
  For a story-like sentence, lorong usually sounds more natural.

You’d typically add a subject like saya/aku and use mendengar or bisa mendengar:

• Saya bisa mendengar suara langkah di lorong malam ini. Or more natural in many contexts:
• Saya dengar suara langkah di lorong malam ini. (informal)

Indonesian word order is fairly flexible as long as it stays clear. These are all workable with slightly different emphasis:

• Suara langkah di lorong terdengar begitu jernih malam ini. (neutral)
• Malam ini suara langkah di lorong terdengar begitu jernih. (time emphasized)
• Di lorong, suara langkah terdengar begitu jernih malam ini. (location emphasized)