Possible Clues:

• One knows what it's like, by the sound of it
• One knows the sound of this way on the face of it
• With 53-down, allergic reaction
• Like sounds of m, n, ng
• Of sound, as if it came through the nose
• Some men, as always, like the sound from an organ
• Rocket scientists heading for launch via central feature
• Like an 'eh,' maybe
• One knows it's something about that sound
• Point to a little girl with adenoids