Challenge 1: Why Noise Reduction Precedes Normalizing in This Capstone — Solution Walkthrough

The answer:

Per Chapter 3's own material, normalizing raises a recording's overall
volume evenly — it can't distinguish the wanted voice signal from
unwanted background noise, so normalizing first would raise both the
hosts' voices and the room's own background hum together. Running
noise reduction first removes that hum while it's still at its
original, unboosted level.

Why this order specifically matters in this capstone:

Step 3 samples a noise profile from the room tone identified back in
Step 1 and removes it across the full recording. Only after that
cleanup does Step 4 normalize both hosts' tracks to a consistent
target level — meaning the target volume reflects the actual wanted
dialogue, not a mix of dialogue and leftover noise.

What would have gone wrong in the opposite order:

Had Step 4 come before Step 3, the room hum would have been
normalized right along with the hosts' voices, then noise reduction
would be working against an already-louder version of that same noise
— a less clean result than reducing it before any boosting happened.

WHY THIS WORKS AS AN ANSWER
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This exercise checks that the noise-reduction-before-normalizing order
is correctly traced back to Chapter 3's own explanation of why
normalizing can't distinguish signal from noise.