As we know from con­ver­sa­tions in sub­way tun­nels or singing in the show­er, dif­fer­ent kinds of spaces and build­ing mate­ri­als alter the qual­i­ty of a sound. It’s a sub­ject near and dear to archi­tects, musi­cians, and com­posers. The rela­tion­ship between space and sound also cen­tral­ly occu­pies the field of “Acoustic Arche­ol­o­gy.” But here, an unusu­al prob­lem presents itself. How can we know how music, voice, and envi­ron­men­tal sound behaves in spaces that no longer exist?

More specif­i­cal­ly, writes EurekAltert!, the ques­tion that faced researchers at the Uni­ver­si­ty of Seville was “how did words or the rain sound inside the Mosque of Cor­do­ba in the time of Abd al-Rah­man I?” The founder of an Iber­ian Mus­lim dynasty began con­struc­tion on the Mosque of Cor­do­ba in the 780s. In the hun­dreds of years since, it under­went sev­er­al expan­sions and, lat­er, major ren­o­va­tions after it became the Cathe­dral of Cor­do­ba in the 13th cen­tu­ry.

The archi­tec­ture of the 8th cen­tu­ry build­ing is lost to his­to­ry, and so, it would seem, is its care­ful sound design. “Unlike frag­ments of tools or shards of pot­tery,” Atlas Obscu­ra’s Jes­si­ca Leigh Hes­ter notes, “sounds don’t lodge them­selves in the soil.” Archeo-acousti­cians do not have recourse to the mate­r­i­al arti­facts arche­ol­o­gists rely on in their recon­struc­tions of the past. But, giv­en the tech­no­log­i­cal devel­op­ments in reverb sim­u­la­tion and audio soft­ware, these sci­en­tists can nonethe­less approx­i­mate the sounds of ancient spaces.

In this case, Uni­ver­si­ty of Seville’s Rafael Suárez and his col­lab­o­ra­tors in the research group “Archi­tec­ture, Her­itage and Sus­tain­abil­i­ty” col­lect­ed impulse responses—recordings of reverberation—from the cur­rent cathe­dral. “From there, they used soft­ware to recon­struct the inter­nal archi­tec­ture of the mosque dur­ing four dif­fer­ent phas­es of con­struc­tion and ren­o­va­tion.… Next, they pro­duced aural­iza­tions, or sound files repli­cat­ing what wor­ship­pers would have heard.”

To hear what late-8th cen­tu­ry Span­ish Mus­lims would have, “researchers used soft­ware to mod­el how the archi­tec­ture would change the same snip­pet of a record­ed salat, or dai­ly prayer. In the first con­fig­u­ra­tion, the prayer sounds full-bod­ied and sonorous; in the mod­el that reflects the mosque’s last ren­o­va­tion, the same prayer echoes as though it was recit­ed deep inside a cave.” All of those ren­o­va­tions, in oth­er words, destroyed the son­ic engi­neer­ing of the mosque.

As the authors write in a paper recent­ly pub­lished in Applied Acoustics, “the enlarge­ment inter­ven­tions failed to take the func­tion­al aspect of the mosque and gave the high­est pri­or­i­ty to main­ly the aes­thet­ic aspect.” In the sim­u­la­tion of the mosque as it sound­ed in the 780s, sound was intel­li­gi­ble all over the build­ing. Lat­er con­struc­tion added what the researchers call “acoustic shad­ow zones” where lit­tle can be heard but echo.

Unlike Hagia Sofia, the Byzan­tine cathe­dral-turned-mosque, which retained its basic design over the course of almost 1500 years, and thus its basic sound design, the Mosque-Cathe­dral of Cor­do­ba was so altered archi­tec­tural­ly that a “sig­nif­i­cant dete­ri­o­ra­tion of the acoustic con­di­tions” result­ed, the authors claim. The mosque’s many remain­ing visu­al ele­ments would be famil­iar to 8th cen­tu­ry atten­dees, writes Hes­ter, includ­ing “gilt cal­lig­ra­phy and intri­cate tiles… and hun­dreds of columns—made from jasper, onyx, mar­ble, and oth­er stones sal­vaged from Roman ruins.” But the “acoustic land­scape” of the space would be unrec­og­niz­able.

The spe­cif­ic sounds of a space are essen­tial to mak­ing “a place feel like itself.” Some­thing to con­sid­er the next time you’re plan­ning a major home ren­o­va­tion.

via Atlas Obscu­ra

Relat­ed Con­tent:

Hear the Hagia Sophia’s Awe-Inspir­ing Acoustics Get Recre­at­ed with Com­put­er Sim­u­la­tions, and Let Your­self Get Trans­port­ed Back to the Mid­dle Ages

The Same Song Sung in 15 Places: A Won­der­ful Case Study of How Land­scape & Archi­tec­ture Shape the Sounds of Music

David Byrne: How Archi­tec­ture Helped Music Evolve

Josh Jones is a writer and musi­cian based in Durham, NC. Fol­low him at @jdmagness.