Short Answer:
Yes. Narrowing receiver bandwidth reduces the amount of noise entering the receiver and often improves readability.
Why It Works:
Noise power increases as receiver bandwidth increases. When you reduce bandwidth, less noise energy is passed to the audio stage, while the desired signal remains mostly unchanged.
Important Limitation:
Bandwidth should not be narrowed so much that it distorts the signal or removes important audio information.
Elmer Tip:
Clear signals are not always loud signals. A quieter, narrower signal is often easier to understand.
Next Step:
Gradually reduce receiver bandwidth while listening to a signal and stop when clarity begins to drop.