A large number of VoIP analysis tools rely on definitive but somewhat generic measurements- packet loss, latency and jitter, to name three.
But now we are seeing tools that offer far more sophisticated measuring and evaluation capabilities.
ACQUA-IP Compact VoIP-Speech Quality Test System is one of them. From Germany-based HEAD Acoustics, This is a dual-channel analyzer that can measure such criteria as frequency response in both the sending and receiving direction, echo attenuation under single talk conditions, and sending and receiving loudness ratings.
Even more interesting, ACQUA-IP cam measure one-way speech transmission quality in either the sending and receiving direction. The analyzer does this by means of TOSQA (Telecommunications Onjective Speech Quality Assessment), a technology that can objectively model the results of listening tests. They provide a result that could be expected if the recorded speech were subjectively rated by test persons.
TOSQA allows the assessment of terminals as part of the transmission path because it is validated for both acoustical and electrical interfaces as well as wideband measurements.
Lots of calculations, but in a cool spectrographic and 3-D display, too.
Pricing varies widely, and is available only on request.