The OS-2740 is package software consists of the OS-2700 and plug-in options including sound quality evaluation software. This software quantify sound by using six parameters of psychoacoustic evaluation; loudness, sharpness, roughness, fluctuation strength, AI (Articulation Index), tonality as well as conventional physical quantities such as frequency analysis or octave analysis.
Comparative evaluation of recorded data assessed by time axis or second processing of calculated results by sound quality parameters can produce new original parameters to extract features in sound to be measured. The OS-2740 Sound Quality Evaluation software achieves improving of sound quality, reducing cost of test, speed-up of development period and so on.
This software allows you to qualify subjective evaluation by the following six sound quality evaluation parameters, and makes clear which factor brings about annoying sense.
Various editing can easily be performed by mouse dragging or numerical input, such as specified range of partial delete or cut, increase and decrease of amplitude level, taper processing. Combining file or re-sampling can be also available.
You can change filter coefficient freely while hearing those sound to perform re-analysis of the data.
Example 1: Efficient noise reduction
When noise is generated mixed with an engine noise, any characteristics cannot be found by FFT analysis. You don’t know how much noise should be reduced enough not to be annoyed. On the other hand, Loudness analysis can perform noise reduction efficiently by using masking effect of engine sound.
* The specific target noise reduction level of "3 sone = 15 dB" can be obtained by masking curve threshold of engine sound.
Example 2: Noise becomes clear by the Fluctuation Strength Analysis
When time fluctuation noise is inaudible hidden in engine sound after an engine warm-up even though it had been heard before engine warm-up, the fluctuation strength analysis focused on time fluctuation component is effective to make the noise features clear, which cannot be figured out by the octave analysis. The results of fluctuation strength analysis reflect on the changes of engine sound before/after warm-up.