Related Clues:

• Belly up, journalist becomes less emphatic
• Mum needs energy to visit SA capital, missing nothing
• Listen another way, as it's inaudible
• Listen trembling on the QT
• Perhaps the artist is an avant-garde 8, taking in two students
• Mum is upset -- time to give things up?
• Unheard
• Like a reading room
• Making little noise
• With 56-Down, pre-talkies time
• Quiet — 13 (anag)
• Making no sounds
• Like lead character of knight, say, in old film
• Softened, as sound
• Toned down, as a trumpet