del.icio.usHow to take part in testing
Testing is really easy and looks more like fun. You don’t need to have extraordinary hearing abilities or expensive audio equipment. Any PC with soundcard and headphones is OK. Any person, being able to hear, can be the expert in SoundExpert testing room.
A single testing session consists of three easy steps:
- downloading of a test file
- listening it
- sending back of a grade.
1. Download a test file
Just click the link below and save zip file (≈3Mb) to your computer as usual. You can use any browser or download manager with resume option. If you encounter difficulties downloading test files, try to use passive FTP mode (standard workaround for the users behind a firewall). Use with care segmented downloading (optionally used for download acceleration in some download managers), because every test file could be downloaded only once and if the last segment is finished first SoundExpert will terminate downloading of a whole file.
Test file is a zip archive that contains two files: “se_test.wav” and “readme.htm”. The name of your zip file is a unique identificator of enclosed sound file. Please, keep it safe until you sent back your judgment to SoundExpert.
2. Listen and make your judgment
Audio file “se_test.wav” includes two samples of the same sound excerpt. One of them is a reference sound material and the other is processed by device under test. You have no information either about order of samples or about device being tested. Sound excerpts for this project were selected according to AES recommendations. The whole set of sound excerpts consists of nine different pieces. Each time you download a test file from SoundExpert you get random sound excerpt and testing device.
The format of “se_test.wav” is uncompressed PCM 44100Hz 16bit Stereo, so you can use almost any player to listen to it. It is recommended to turn off all equalizations and sound enhancements in your player/sound card and set the volume to the level you normally listen your audio. The use of headphones is preferable unless you are the owner of professional or Hi-End audio installation. You might need to listen the test file for several times until you can answer two questions:
- What sample - the first or the second, do you think, has degraded sound quality?
- What is the difference between degraded and reference samples:
- imperceptible (5th grade)
- perceptible but not annoying (4th grade)
- slightly annoying (3d grade)
- annoying (2nd grade)
- very annoying (1st grade)
The more accurate grades - the more reliable ratings!
It's a good practice to download 3-5 test files at once, listen them all and guess your grades. By doing that you’ll become familiar with the above five-grade impairment scale. Then you can grade them conclusively and proceed to the next step.
3. Send back your grade
After you have made your judgment you can send it to SoundExpert by filling the form below:
Thank You for participation. You can take part in testing as many times as you like.