reunite

A voice echoing in a dark hallway that is fill with blood natsumi rush over as she know the voice that is echoing

In audio signal processing and acoustics, echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the listener. Typical examples are the echo produced by the bottom of a well, by a building, or by the walls of an enclosed room and an empty room. A true echo is a single reflection of the sound source.[citation needed]

The word echo derives from the Greek ἠχώ (ēchō),[1] itself from ἦχος (ēchos), "sound".[2] Echo in the Greek folk story is a mountain nymph whose ability to speak was cursed, leaving her able only to repeat the last words spoken to her. Some animals use echo for location sensing and navigation, such as cetaceans (dolphins and whales) and bats.Acoustic phenomenon Acoustic waves are reflected by walls or other hard surfaces, such as mountains and privacy fences. The reason of reflection may be explained as a discontinuity in the propagation medium. This can be heard when the reflection returns with sufficient magnitude and delay to be perceived distinctly. When sound, or the echo itself, is reflected multiple times from multiple surfaces, the echo is characterized as a reverberation In music In music performance and recording, electric echo effects have been used since the 1950s. The Echoplex is a tape delay effect, first made in 1959 that recreates the sound of an acoustic echo. Designed by Mike Battle, the Echoplex set a standard for the effect in the 1960s and was used by most of the notable guitar players of the era; original Echoplexes are highly sought after. While Echoplexes were used heavily by guitar players (and the occasional bass player, such as Chuck Rainey, or trumpeter, such as Don Ellis), many recording studios also used the Echoplex. Beginning in the 1970s, Market built the solid-state Echoplex for Maestro. In the 2000s, most echo effects units use electronic or digital circuitry to recreate the echo effect.

This illustration depicts the principle of sediment echo sounding, which uses a narrow beam of high energy and low frequency

The human ear cannot distinguish echo from the original direct sound if the delay is less than 1/10 of a second.[3] The velocity of sound in dry air is approximately 343 m/s at a temperature of 25 °C. Therefore, the reflecting object must be more than 17.2m from the sound source for echo to be perceived by a person located at the source. When a sound produces an echo in two seconds, the reflecting object is 343m away. In nature, canyon walls or rock cliffs facing water are the most common natural settings for hearing echoes. The strength of echo is frequently measured in dB sound pressure level (SPL) relative to the directly transmitted wave. Echoes may be desirable (as in sonar) or undesirable (as in telephone systems).

Natsumi run towards the voice using talisman as item to vanguish the demons that is in her way

In Japanese religion, an ofuda (お札 or 御札, honorific form of fuda, "slip (of paper), card, plate") is a talisman made out of various materials such as paper, wood, cloth or metal. Ofuda are commonly found in both Shinto shrines and Buddhist temples and are considered to be imbued with the power of the deities (kami) or Buddhist figures revered therein. Such amulets are also called gofu (護符).

A specific type of ofuda is a talisman issued by a Shinto shrine on which is written the name of the shrine or its enshrined kami and stamped with the shrine's seal. Such ofuda, also called shinsatsu (神札), go-shinsatsu (御神札) or shinpu (神符), are often placed on household Shinto altars (kamidana) and revered both as a symbol of the shrine and its deity (or deities) - indeed containing the kami's essence or power by virtue of its consecration - and a medium through which the kami in question can be accessed by the worshiper. In this regard they are somewhat similar to (but not the same as) goshintai, physical objects which serve as repositories for kami in Shinto shrines.

Other kinds of ofuda are intended for a specific purpose (such as protection against calamity or misfortune, safety within the home, or finding love) and may be kept on one's person or placed on other areas of the home (such as gates, doorways, kitchens, ceilings). Paper ofuda may also be referred to as kamifuda (紙札), while those made of wood may be called kifuda (木札). Omamori, another kind of Japanese amulet, originated and may be considered as a smaller, portable version of ofuda The practice of creating gofu originated from Onmyōdō - which adopted elements of Daoism - and Buddhism. Indeed, such ofuda and omamori were heavily influenced by the Daoist lingfu. Later, similar talismans also came to be produced at Shinto shrines.[1][2][3][4][5] The three shrines of Kumano in Wakayama Prefecture were particularly famous for their paper talisman, the Kumano Goōfu (熊野牛王符, 'Kumano Ox King Talisman'), also known as the Goōhōin (牛王宝印), which were stamped on one side with intricate designs of stylized crows.[6][7][8] During the medieval period, these and similar gofu produced by other shrines were often employed in oath taking and contract drafting, with the terms of the oath or agreement being written on the blank side of the sheet.[9][10][11][12] In 1871, an imperial decree abolished the oshi and allotted the production and distribution of the amulets, now renamed Jingū Taima, to the shrine's administrative offices.[14] It was around this time that the talisman's most widely known form - a wooden tablet containing a sliver of cedar wood known as gyoshin (御真, "sacred core")[13][17] wrapped in paper on which is printed the shrine's name (天照皇大神宮, Tenshō Kōtai Jingū) and stamped with the seals of the shrine (皇大神宮御璽, Kōtai Jingū Gyoji) and its high priest (大神宮司之印, Daijingūji no In) - developed. In 1900, a new department, the Kanbesho (神部署, "Department of Priests"), took over production and distribution duties. The distribution of Jingū Taima was eventually delegated to the National Association of Shinto Priests (全国神職会, Zenkoku Shinshokukai) in 1927 and finally to its successor, the Association of Shinto Shrines, after World War II.[14] The Association nowadays continues to disseminate Jingū Taima to affiliated shrines throughout Japan, where they are made available alongside the shrines' own amulets.