Notre Dame de Paris is scheduled to reopen in 2024, before the Paris Olympic Games, but there’s still a lot of work to complete before then. The art and statues – not to mention the gigantic organ – must be completely cleaned and restored and the iconic spire must be reraised. While there are a variety of projects underway to restore the cathedral’s look, there’s a much greater battle taking place to restore the soundscape of the French monument.
In a recent analysis of the damage to Notre Dame, The New York Times reported that experts estimate the building lost around 20% of its acoustics in the 2019 fire. This damage to what is described as a “sonic fingerprint” comes due to the three large holes made in the ceiling, as well as many other damages that occurred when the spire collapsed into the building.
Every little detail of a room or building can have a great influence on its “sonic fingerprint,” from the materials used to make the walls, floors, and ceilings, to the various adornments that decorate them. The article notes that two different analyses of Notre Dame’s acoustics, one from 1987 and the other from 2015, were vastly different, when the only change to the space in that time was the addition of a carpet strip that was installed down the main aisle.
The importance of sound to a space, especially a worship space, has been increasingly recognized by experts and has spurred several new fields of research. NYT spoke with Brian Katz, who is an “acoustic consultant” working to recapture the iconic soundscape of Notre Dame, who uses advances in technology to compare recordings from Notre Dame before the fire against ones he has taken since its destruction.
To take these recordings within the compromised structure, Katz had to equip a robot – made to inspect cramped sewer pipes – with microphones and send it into Notre Dame. These recordings helped him to identify just how much of Notre Dame’s acoustics have been lost, but with so many factors contributing to the sound space, it is not so easy to fasten down the culprits. Of course the holes in the ceiling were a factor, but so too was the lack of pews (removed during the restoration effort), as well as the lack of visitors, and even the art, which has been removed for restoration.
The analyses of the old recordings put against the new can highlight the things that were lost, but they can also suggest routes to improvement. Katz noted that worship spaces in particular are difficult because there are many different kinds of sounds that they must facilitate. Sound spaces that best capture hymns and concerts are not necessarily the same that would allow a congregation to hear a homily from the pulpit.
“There’s no perfect acoustics” for a space, Katz says, “but every action or every use has its ideal acoustics.”
As he explains: “If I want to hear the singing of the clergy doing polyphonic music, as they did in the Middle Ages, there is an acoustic that’s best suited to that. If I then go forward to when the preacher is now preaching in a language known by the public, and I want to be able to understand it, that’s going to require a different acoustics.”
As Notre Dame enters a pivotal stage in its reconstruction, experts like Katz are working to ensure that Notre Dame’s acoustics can be brought back as they were before, with an eye for improving them as well.
Read more about the work going on at Notre Dame in this in-depth article for the New York Times, which includes an interactive virtual tour of the building that highlights the areas in which the most damage was done to the building's acoustics.
