How to read the ratings
The rating bar consists of the following elements:
- Device or technology being tested.
- Value of actual perceived audio quality (rating) which is also indicated
by the bar length . Anchor points could be interpreted as follows:
In most cases using this device/technology:
1.0 – you will hear heavily distorted sound
2.0 – you will hear unpleasant sound artifacts
3.0 – you will hear distinctly audible but tolerable sound artifacts
4.0 – you will hear faintly discernible sound artifacts
5.0 – you will not hear any sound artifacts
above 5.0 – all sound artifacts will be beyond threshold of human perception with corresponding perception margin
and - "low" and "high" of rating. As each device is tested with nine different sound samples, there are nine different local ratings for a device. In fact, the actual rating is an average of those nine local ratings. The highest and the lowest ones are indicated. Big gap between them means that sound quality of device/technology is not consistent enough. It varies with type of sound material: music of different genres and complexity, voice with or without music, noisy/clear recordings etc. The lowest local rating is more important in this sense as it indicates worst case behavior of tested device.
- Accuracy of rating. It is also indicated by the color of bar - more accurate ratings have darker bars and less percentage values. Accuracy depends on number of grades returned by participants. In most cases 5% or less is OK.
- Ruler for convenient estimation of "highs" and "lows".
For devices with small impairments (not audible in ordinary listening tests) SoundExpert amplifies their sound artifacts to some predefined extent. Ratings of such devices are calculated analytically taking into account both the grades received and the amplification applied. They are above 5th grade on the scale showing certain quality headroom of such devices.