SCP Foundation: Entries

SCP-2167

Item #: SCP-2167

Object Class: Euclid

Special Containment Procedures: SCP-2167 is to be stored in a soundproofed containment locker, connected to a CD player, four 5W speakers measuring at minimum 4 on the infinite grade impairment scale (hereafter IGIS), and a 12VDC 5A uninterruptible power supply with at least 300 amp-hours of capacity. The speakers are to be positioned around SCP-2167 at 90±5° angles at a maximum distance of 0.5 m. The locker is also to contain a small number of music CDs and vinyl records containing non-sensitive material alongside SCP-2167.

All adjustment knobs on SCP-2167 are to be kept at the minimum possible value. The CD player is to be configured to continuously play classical music at a very low volume.

No other speakers or audio devices are to be brought within 10 m of the containment area at any time, or used in areas directly above or below containment. All sound recordings are to be stored securely and deleted once no longer needed.

SCP-2167 is to be internally inspected at least once per month for any signs of wear or potential failure of any of its components. Any components showing signs of wear are to be replaced. All electrolytic capacitors are to be tested, and any capacitor showing values outside its nominal tolerance is to be replaced with an equivalent part.

All testing is to be conducted in a soundproofed room measuring 4.8 m wide, 7.8 m long, and 3 m high. Except per specific testing protocol, SCP-2167 is to remain connected to the CD player and UPS at all times. During standard testing it is to be connected to a pair of 25W speakers scoring at minimum 5 on the infinite grade impairment scale. The speakers and a chair are to be positioned in a golden cuboid arrangement as per document 2167-F.

Description: SCP-2167 is a "Gauchito-78" audio amplifier measuring 100mm wide, 190mm long, and 60mm thick. The amplifier case is made of unpainted cast aluminum-zinc. The front face of the device has three adjustment knobs, with the labels "gain", "volume", and "tone" etched into the case, as well as a script logo giving the device name and an unknown graphic icon. It possesses two 1/4" audio jacks located on either side of the device, and a 12VDC barrel jack located in the top edge.

When connected to a set of speakers, a power supply, and an audio source via the jacks on its sides, SCP-2167 will function as a signal amplifier, amplifying the signal voltage according to the position of the "gain" knob, and performing high-frequency filtering according to the position of the "tone" knob.

Computer measurements of the audio output indicate that the physical intensity of sound emitted from a speaker driven by SCP-2167 is typical for a hobby audio amplifier. However, any subject who listens to SCP-2167's output will perceive it as being much louder than would be expected for non-anomalous sound with the same physical intensity. The perceived loudness corresponds to the position of the "volume" knob.

The psychoacoustic loudness Sout, measured in sones, is characterized by Equation (), where Sin is the expected loudness as determined from physical measurement, kv is the position of the "volume" dial in the range 0-10, and ㅐ(m,n) is the real extension of the Ackermann–Péter function.

(1)Sout=ㅐ(kv,c1Sin)

c1 has been experimentally determined to be approximately 0.93.

Experiments with volume settings higher than around 4.5 have not been able to determine if this trend continues, as the intense pain interferes with the subject's ability to accurately gauge the loudness.

Chronic exposure to SCP-2167 does result in permanent hearing damage as would be expected from non-anomalous sounds played at the perceived volume, but does not lead to total hearing loss. Acute exposure over a short period does not result in permanent hearing loss.