| LPFN | low-pass filtered noise |
|---|---|
| MNA | maximum noise area |
| NAC | N-acetylcysteine; National Asthma Center; National Audiovisual Center; Noise Advisory Council |
| NC | nasal cannula; nasal clearance; neck complaint; neonatal cholestasis; neural crest; neurologic check... |
| NDT | neurodevelopmental treatment; noise detection threshold; nondestructive test, nondestructive testing... |