What is the packet loss threshold for voice when sustained losses become noticeable?

• A. 0%
• B. 0.5%
• C. 1%
• D. 2%

Answer: (C)

Voice traffic is highly sensitive to packet loss because each lost packet can create a gap in the audio stream. While codecs can conceal some occasional losses, when losses are sustained, the gaps become audible and disrupt the rhythm of speech. Around 1% sustained loss is the point where listeners typically begin to notice degradation in voice quality. Below this, many listeners won’t perceive a problem; above it, quality worsens noticeably. So the best choice is 1%. In practice, engineers aim to keep loss well under 1% and supplement with QoS, buffering, and reliable paths to protect voice.