https://phys.org/news/2018-11-recreating-islamic-mosque-cordoba.html

"The mosque founded by Abd al-Rahman I responded acoustically to Muslim liturgical requirements, providing a living space that favoured their majesty. Later expansions gave a formal appearance of superposition on the pre-existing space. However, notable sound differences were produced in the interior space. This, united with the increase in depth caused by the expansion of Abd al-Rahman II, meant a reduction in the acoustic quality of the areas furthest away from the qibla wall," explains the University of Seville professor Juan José Sendra.

With the expansion of Al-Hakam II, two acoustically juxtaposed mosques were obtained. The last lateral expansion, by Al-Mansur, in which even the mihrab was decentred with respect to the new layout, was separated from the rest of the building, with a clear degradation in the quality of verbal communication.