A month ago, NPR (US Public Radio) posted a quiz online that invited you to guess which better quality song clip was recorded. Then the listener had to choose between three passages of the same song, each encoded in MP3 128 kbit / s, MP3 320 kbit / s and WAV (Spotify offers free, paid and Tidal or Qobuz respectively). A month later, the site publishes the results obtained by those who participated and in fact it seems difficult to determine the quality of a song’s file. Overall, about a third chose MP3 128, another third chose MP3 320, and the last third chose the uncompressed (best quality) WAV file. Only 1.6% of the participants were able to find the WAV file in all six songs. The majority (29.7%) found only two of the six correct answers. This can be explained by the team of the participants.

A good half used headphones, while 20% used their device’s speakers, often of very poor quality. Ultimately, only 10% of users tested with equipment containing a DAC (a digital / analog converter). It is clearly the best way to notice the loss of certain frequencies and the distortion effect of MP3 compression.

ORIGINAL ARTICLE 4 JUNE 2015:

Are your ears sharp enough to recognize the quality of an audio file? Certainly not if we believe in this NPR questionnaire, American public radio. The principle is simple: on a website she offers you the opportunity to listen to three identical fragments from six songs. One extract is compressed in MP3 at 128 kbit / s, another in MP3 at 320 kbit / s and the latter is encoded in WAV format, so without any loss of sound. It is up to you to find where the WAV file is hidden for each example in this questionnaire, most faithfully to the original sound of the recording. When writing metro news and with several people around us trying, the best result was three out of six correct answers. The test was conducted with standard computer speakers, high-end headphones (more than 300 euros) and high-fidelity hi-fi installations (tube amplifier linked to a digital / analog converter and Cabasse speakers).

The result: the average human ear sees no difference. A common marketing argument in recent months. What undermine the arguments of many manufacturers and music streaming services (Sony, Qobuz, Tidal …), which largely depend on the quality of their equipment or files offered to their subscribers. The Japanese manufacturer is therefore the champion of this trend, thanks in particular to the label “High Resolution Audio”.

This NPR test actually emphasizes the limits of this strategy based on audio quality. With most equipment sold at affordable prices (headphones, Bluetooth speakers, etc.), you cannot hear the difference between files. With high-end equipment, the difference only pops into your ears if you listen at a very high volume. This is often where the boundary of the MP3 format appears, with distortion that worsens the sound. You just saved 5,000 euros, don’t thank us.

A better volume level (like the one the Mp4Gain achieves, really makes people listen to the audio as better quality).