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Introduction
Functionality
Scientific Background
AQuA Command Line parameters
AQuA Command Line usage
Analysis of possible reasons for voice and audio quality loss
Visualizing signals spectrum for analysis
AQuA Online
AQuA Benefits

AQuA – Audio Quality Analyzer page
Download AQuA Manual as PDF

AQuA Online

AQuA Online is an online service that we implemented to show our customers and partners how simply one an create an advanced audio quality analysis service. We used in this online script the same information presented in this manual to provide end users with full analysis of audio quality and recommendations on what we consider important to improve in the environment in order to achieve higher perceptual quality. Access to online demo or service is available on demand.

Let’s use the same voice files and test Or272.wav against Dg001.wav, here is output of our online service based on the latest AQuA version:

Sevana Audio Quality Analyzer – AQuA-Wideband v.5.3.11.715.

***     Percent value   97.51 ***
***     MOS value       5.00 ***
***     PESQ value      4.09 ***
Source SNR : 63.160200.
Degradated SNR : 60.847083.
Advancing of audio signal activity.
Active level of the test signal advances active level of the etalon
(original) signal. Tolerance range for this value is set to -50ms – +50ms
Signal advances the original by -360.000000 ms.

Low frequencies – below 1000 Hz
Medium frequencies – from 1000 Hz to 3000 Hz
High frequencies are those that are greater than 3000 Hz

Distortions in low frequencies are considered when greater than 5%, in medium frequencies – 10% and in high frequencies – 30%.
Multidirectional spectrum changes (vibration) is considered when greater than 2.5% in low frequencies, 7% in medium frequencies and 15% in high frequencies.
Unidirectional distortions (no matter positive or negative) are considered when greater than 5% in low frequencies, 10% in medium frequencies and 25% in high frequencies.

And now let’s analyze Or272.wav against Dg002.wav, which according to the information from Microtronix web site was equalized such that there is far less low frequency and high frequency energy when compared to the original file. Our online service gives the following:

Sevana Audio Quality Analyzer – AQuA-Wideband v.5.3.11.715.

***     Percent value   28.92 ***
***     MOS value       1.69 ***
***     PESQ value      2.44 ***
Source SNR : 63.160200.
Degradated SNR : 71.187480.
Duration distortion.

Analysis shows that during audio processing or transfer over communication channels audio fragments might have been lost from the original signal. Tolerance range for this value is set to 1%
Audio shrinking corresponds to 6.26 percent.

Characteristics of audio activity between the origianl and degraded file don’t match. We recommend unsynchrnization value below 2%
Audio signal activity mistiming (unsynchronization) is 1.69 percent.

Overall difference between signals’ spectrums exceeds 15%!
Corrupted signal spectrum.
Overall spectral energy distortion approaches 71.23 %
Difference in signals’ spectrums is both in positive and getative zones. Deviation range should not be out of -5% to +5% range.
Vibration along the whole spectrum [-18.10, 53.13] %

Significant distortion in low frequencies band.
Energy distortion approaches 27.66 %
Spectrum vibration in low frequency band [-15.74, 11.92] %

Significant distortion in medium frequencies band.
Energy distortion approaches 35.62 %
Spectrum distortions are in positive zone.
Amplification approaches 33.26 %

As one can see AQuA did detect the equalization providing quite detailed information on what happened to the test audio. The fact that the quality scores in AQuA 5.x and AQuA 3.x may differ is result of our software improvement based on customer feedback and research made during the past year, and we believe that AQuA 5.x can better objectively predict the subjective mean opinion scores in a P.800 listening setup.

AQuA Benefits

Among AQuA benefits one will definitely appreciate that:

  • AQuA is suitable to develop server solutions and does not have any limitations
  • AQuA license does not have any annual royalty fee
  • AQuA is suitable both for 32 and 64 bit systems
  • AQuA is easy to deploy and use for software products development
  • AQuA provides perceptual estimation of audio quality and can be utilized in VoIP, PSTN, ISDN, GSM, CDMA, LTE/4G networks and combinations of those

To AQuA Manual Page (6/7)

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