1 Conversational Speech Quality - The Dominating Parameters in VoIP Systems H.W. Gierlich, F. Kettler HEAD acoustics GmbH • Typical IP-Scenarios: components and their influence on speech quality • testing techniques for speech quality parameters, selected examples • Summary and future work
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Conversational Speech Quality -The Dominating Parameters in
VoIP Systems
H.W. Gierlich, F. Kettler
HEAD acoustics GmbH
• Typical IP-Scenarios: components and their influence on speech quality
• testing techniques for speech quality parameters, selected examples
analysis of thebackground noisewhen call was puton hold(example from thebeginning)
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Background noise in sendingsimultaneously with receivingsignal (from loudspeaker)
transmitted signal insending
power densityspectrum
Original -34,6 dBm0comfort noise -36,2 dBm0
spectralanalysis
Comfort noise insertion analysis (example)
Relative Approach analysis
Summary
Summary and outlook:
- Speech quality influenced by * condition and load of the network * interaction of network components * interaction of terminal and network * environmental conditions at the users location
- Test methods available for various parameters
- Further investigations needed on noise transmission „overall quality“ - number