in a low voice 的近义词 13 个

• softly
• faintly
• in a whisper
• in low tones
• in silence
• inaudibly
• murmuring
• noiselessly
• sotto voce
• soundlessly
• tacitly
• under one's breath
• weakly

in a low voice 的反义词 3 个

• audibly
• loudly
• publicly