The FVSA has NO competitors, because it is a 4th Generation Totally NEW development from Australia, produced in 2006, not mimicking old Technology that has been very controversial to say the least.
The FVSA © does NOT use the Fourier (FFT) nor the Bell – McQuiston Algorithm basis of the 1940s & 1970s that other Instruments are based on & were digitised in the early 1990s.
In 2008 a Scientific paper on ‘Analysis in Speech’ mentioned that these do NOT capture the Total variation of each utterance, & also the old VSAs are claim to be measuring a small section of 8 – 12/14 Hz frequency which is a ‘muscle microtremor’. As the Microphones used by these commence registering from 20Hz – 50Hz (depending on Brand) one would wonder about these “claims”.
Most of these old Technology Instruments were originally Analogue & are still suffering from underdevelopment.
The FVSA is a Total New 21st Century Scientific Development.