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SCP-4XXX: "Echo Echo"
Item #: SCP-4XXX
Object Class: Euclid
Containment Procedures: SCP-4XXX is to be placed in a 3m x 3m x 3m containment unit with an airtight seal and lined with acoustic-dampening material. Unless an testing with SCP-4XXX is in progress, the container must be completely vacuum. This is to prevent the travel of any sound inside the containment unit, specifically reducing the possibility of any sound echoing back into SCP-4XXX. Audio devices capable of recording a wide range of frequencies (.01Hz - 200mHz) are to be installed within the containment area.
Following Incident-4XXX-01, one electrical speaker must also be present inside the containment area.
Description: SCP-4XXX is an immaterial, invisible entity moving freely through space at a constant, unchanging speed. SCP-4XXX's direction, however, changes as it reflects off of a solid surface. SCP-4XXX is observed to constantly emit sounds from various sources, each of these sounds being picked up by SCP-4XXX at some previous time. SCP-4XXX emits these sounds seemingly at random, often emitting more than one sound at once. Over █████ unique sounds have been recorded. Examples of sounds emitted by SCP-4XXX include, but are not limited to:
*Thunder, rainfall, and wind gales
*The whistle of a steam locomotive
*Various instances of bird song from over ██ different species
*Various instances of human vocalizations (numerous variations of "What is that noise?" noted)
*Infrasonic sounds from several earthquakes of varying magnitude
*Echolocation calls from various species of bat
*Shattering glass, likely due to the proximity of high-volume, high-frequency emissions from SCP-4XXX
*Vocalizations of unidentifiable organisms, believed to be [[REDACTED]]
As observed in Incident-4XXX-01 and Incident-4XXX-02, SCP-4XXX is also, in extremely rare cases, able to communicate. It is still unknown if these cases originate from a remote source or from SCP-4XXX itself.
