One of the advantages of the so-called "digital age" is that it allows us to recreate sounds and sound effects that had long been lost to history. One can electronically alter what one hears so that it resembles sounds that were made long ago, but which can't be accurately reproduced today for any number of reasons.
One of those sounds is the Orthodox liturgical chant used in the Hagia Sophia cathedral in Constantinople, later a Moslem mosque following the fall of that city in 1453, and today a museum. The acoustics of the Hagia Sophia were legendary, and added greatly to the impact of the liturgical music used there. A team at Stanford University set out to recreate those acoustics, with amazing results.
With a stunning reverberation time of over 11 seconds, the acoustics of Hagia Sophia were measured and analyzed, and auralized in real-time on Cappella Romana’s performance by the Icons of Sound team at Stanford University.
Lost Voices of Hagia Sophia presents more than 75 minutes of medieval Byzantine chant for the Feast of the Holy Cross in Constantinople, one of the greatest celebrations in the yearly cycle of worship at Hagia Sophia.
A detailed technical explanation of the Hagia Sophia's acoustics may be found here.
Here are three video clips to illustrate the sounds of the cathedral. First, some visual images to accompany the aural effects.
Next, the Prokeimenon from the album, corresponding to the Gradual or Responsorial Psalm in the Catholic Mass, a chanted response to a Scripture reading. The acoustics of the cathedral are electronically overlaid on the performance to produce the correct sound.
Finally, the Cherubic Hymn from the Byzantine Mass, used as a Troparion in that setting.
That's an amazing marriage of modern technology and performance with medieval history. The CD and DVD of the music appear to be sold out at present, but the MP3 album is available.