Stanford University scholars and scientists have worked hard to recreate, digitally, the experience of being at the ancient Hagia Sophia church and mosque in Istanbul, Turkey.
Hagia Sophia was built by Justinian I between 532 and 537, and served as the Byzantine Orthodox Cathedral of Constantinople. Then, for a brief period, it was a Catholic cathedral and after the conquest of Constantinople by the Ottoman Empire, the building was transformed into a mosque, maintaining this function from May 29, 1453 until 1931 when it was secularized. On February 1, 1935 it was inaugurated as a museum.
Can new technologies help us go back in time?
Under this premise the Icons of Sound project was born. The project employs visual, textual and musicological research, the construction of architectural models, auralizations and recordings of Byzantine songs to recreate, digitally, the experience of being in Hagia Sophia as when it was a medieval church.
Hagia Sophia challenges our contemporary expectation of language intelligibility. We are used to hearing the word spoken or sung clearly in dry, non-reverberant spaces to decode the coded message. In contrast, Hagia Sophia’s wet acoustics blur the intelligibility of the message, making the words sound like emanation, emerging from the depths of the sea. It is not surprising that a great part of the ritual in Hagia Sophia involves singing and not recitative discourse.Icons of Sound
Ballon pop recording
The Icons of Sound project focuses on the interior of Hagia Sophia, where scientists and historians used balloon recordings (known as Ballon Pop Recording) in space and other audiovisual research to rediscover the acoustics of the building.
Ballon Pop Recording is a method for experiencing the reverberation time of a place. It is a simple method of creating and recording an impulse response.
An impulse response (or IR) consists of a single impulse sound that has a large amplitude like clapping, a starter pistol or a balloon burst.
By creating an impulsive noise (the bursting of a balloon) in a given space, the sound will radiate omnidirectionally, reflecting off the walls, ceiling, floor and other surfaces around the room. As the sound passes through a series of different reflections, it breaks down until it becomes inaudible. The time it takes for the sound to decay is what is measured. The standard measurement for this is RT60, which refers to the time it takes for the sound to decay by 60dB.
Stanford University published a study with the first recordings in 2009 of Hagia Sophia and the measures taken. https://ccrma.stanford.edu/~njb/research/AES129_Balloon_Slides.pdf
The spatial and temporal dimension of sound
A sound source produces a sequence of air pressure values over time. The sound also interacts with objects, surfaces; the architectural characteristics of the space, in such a way that each pressure value radiated from the source carries an imprint of the space. This impression is called impulse response, and the process of imprinting a space on a sound is called convolution.
Through the response to the impulse and the mechanism of convolution, listening is transformed into a space-time experience.
The first sounds to reach the ear have traveled the shortest distances on their way from source to ear and therefore have interacted with few surfaces and objects. These sounds give us a sense of the geometry of space, source and position.
The later ones, which have interacted many times with the objects in the room, the surfaces and the architectural features, show us a total panorama of the materials and the size of the room.
This is what Hagia Sophia sounds like in the 21st century
On March 27, 2011, at Stanford University’s Center for Computer Research in Music and Acoustics, three choral pieces were recorded for the project with the collaboration of the Cappella Romana choir, the leading chamber choir in the United States dedicated to the performance of early music, Byzantine, Slavic and Gregorian chants.
To recreate the unique sound of Hagia Sophia, the performers sang while listening to the simulated acoustics through headphones. Then the sound of singing was projected through the same acoustic simulator.
The light of other times
Most visitors to the Hagia Sophia museum today cannot experience the subtle changes of light playing through marble and gold because they see the interior in the harsh light of the midday sun or in the light of electricity. Likewise, the relatively short duration of their stay in space prevents them from observing most of the changes of light and brightness that occur there.
In past times it was natural light that moved through the surfaces of marble and gold. The glow simulated the perceptive memory of the trembling sea.
Marmaron in Greek means of marble; Marmara is an inland sea that joins the waters of the Black Sea and the Aegean Sea and therefore separates the Asian part of Turkey from the European part, marmairo and marmarysso mean flash, shine, and marmarygma is reflection.
The Icons of sound project produced a video that explores the aesthetics of Hagia Sophia’s transience, to give an optical dimension to the acoustics, recording the sounds of the doves and wind at dawn and the crowds at midday, thus enriching the listening experience with a recorded Byzantine song.
A project that doesn’t die in time. Sounds without time, sounds that lift and transport you.
Author: Sol Rezza
Editor | Corrector: Franco Falistoco