The measurement campaign was suggested and initiated by Schroeder&Associates as part of the Silent Cities Project, a large-scale participatory environmental monitoring program to document an exceptional change in the urban soundscape due to the economic downturn caused by the restrictions of the COVID-19 pandemic. The Environmental Administration mandated Schroeder&Associés, as a specialized and accredited office, to carry out noise level measurements at 10 pre-selected immission points. In the end, 13 immission points were chosen, now called "IP (Immission Point)", located on the territory of the City of Luxembourg (Millebaach, Cessange, Gasperich, blvd. Royal, Glacis), the Commune of Esch-sur-Alzette (Gare), the Commune of Dudelange (rte de Luxembourg), the Commune of Sanem (Belvaux), the Commune of Mondercange (Pontpierre), the Commune of Diekirch (Sauerwiss), the Commune of Mersch (Lankheck), the Commune of Ettelbrück (rue Pierre Wiser) and the Commune of Walferdange (Heisdorf). Containment measures have led to a strong decrease in human presence in public space. The means of transport (private and public), as well as work and leisure activities, have been considerably reduced. The sounds produced by these activities have decreased in intensity. The purpose of the mission was to measure sound pressure levels in order to collect a sufficient and representative amount of data to produce, through statistical processing, noise indicators representative of the noise environment at the point of immission in the context of the progressive deconfinement after the lock-down decreed from March 15. For 8 of the 13 immission points, noise level data collected during a measurement campaign in 2019 are available. This makes it possible to compare the values established in 2019 with the current values, respectively to observe the evolution of the soundscape during the phase of progressive deconfinement with respect to these reference values.