floor of the CD-quality loop easily. The authors commented: Following criticism that the original published results of the study were not sufficiently detailed, the AES published a list of the audio equipment and recordings used during the tests. Since the Meyer-Moran study in 2007, approximately 80 studies have been published on high-resolution audio, about half of which included blind tests. Joshua Reiss performed a meta-analysis on 20 of the published tests that included sufficient experimental detail and data. In a paper published in the July 2016 issue of the AES Journal, Reiss says that, although the individual tests had mixed results, and that the effect was "small and difficult to detect," the overall result was that trained listeners could distinguish between hi-resolution recordings and their CD equivalents under blind conditions: "Overall, there was a small but statistically significant ability to discriminate between standard quality audio (44.1 or 48 kHz, 16 bit) and high-resolution audio (beyond standard quality). When subjects were trained, the ability to discriminate was far more significant." Hiroshi Nittono pointed out that the results in Reiss's paper showed that the ability to distinguish high-resolution audio from CD-quality audio was "only slightly better than chance." Contradictory results have been found when comparing DSD and high-resolution PCM formats. Double-blind listening tests in 2004 between DSD and 24-bit, 176.4 kHz PCM recordings reported that among test subjects no significant differences could be heard. DSD advocates and equipment manufacturers continue to assert an improvement in sound quality above PCM 24-bit 176.4 kHz. A 2003 study found that despite both formats' extended frequency responses, people could not distinguish audio with information above 21 kHz from audio without such high-frequency content. In a 2014 study, however, Marui et al. found that under double-blind conditions, listeners were able to distinguish between PCM (192 kHz/24 bits) and DSD (2.8 MHz) or DSD (5.6MHz) recording formats, preferring the qualitative features of DSD, but could not discriminate between the two DSD formats. Playback hardware The Sony SCD-1 player was introduced concurrently with the SACD format in 1999, at a price of approximately US$5,000. It weighed over and played two-channel SACDs and Red Book CDs only. Electronics manufacturers, including Onkyo, Denon, Marantz, Pioneer and Yamaha offer or offered SACD players. Sony has made in-car SACD players. In order to playback SACD content digitally without any conversion, some players are able to offer an output carrying encrypted streams of DSD,