Reverse echo

Reverse echo or reverb, also known as backwards echo, is a slightly unusual sound effect created as the result of recording an echo or delayed signal of an audio recording whilst being played backwards. The original recording is then played forwards accompanied by the recording of the echo or delayed signal which is now in reverse.

Invention by Jimmy Page
Guitarist and producer Jimmy Page lays claim to the invention of this effect, stating that he originally developed the method when recording the single "Ten Little Indians" with The Yardbirds in 1967. He later used it on a number of Led Zeppelin tracks, such as "You Shook Me". In an interview he gave to Guitar World magazine in 1993, Page explained:

"During one session [with The Yardbirds], we were recording "Ten Little Indians", which was an extremely silly song that featured a truly awful brass arrangement. In fact, the whole track sounded terrible. In a desperate attempt to salvage it, I hit upon an idea. I said, "Look, turn the tape over and employ the echo for the brass on a spare track. Then turn it back over and we'll get the echo preceding the signal." The result was very interesting -- it made the track sound like it was going backwards.

Later, when we recorded "You Shook Me", I told the engineer, Glyn Johns, that I wanted to use backwards echo on the end. He said, "Jimmy, it can't be done". I said "Yes, it can. I've already done it." Then he began arguing, so I said, "Look, I'm the producer. I'm going to tell you what to do, and just do it." So he grudgingly did everything I told him to, and when we were finished he started refusing to push the fader up so I could hear the result. Finally, I had to scream, "Push the bloody fader up!" And lo and behold, the effect worked perfectly.

Other songs using this effect

 * "Whole Lotta Love" by Led Zeppelin on the album Led Zeppelin II
 * "When the Levee Breaks" by Led Zeppelin on the album Led Zeppelin IV
 * "The Wanton Song" and "Sick Again" by Led Zeppelin on the album Physical Graffiti
 * "Megalomania" by Black Sabbath on the album Sabotage
 * "Back Street Kids" by Black Sabbath on the album Technical Ecstasy
 * "Eternal Idol" by Black Sabbath on the album The Eternal Idol
 * "Arise" by Sepultura on the album Arise
 * "Even Flow" by Pearl Jam on the album Ten
 * "Hurt" by Nine Inch Nails on the album The Downward Spiral
 * "Let My Love Open the Door" by Pete Townshend on the album Empty Glass
 * "Mutilated Lips" by Ween on the album The Mollusk
 * "Shout at the Devil" by Mötley Crüe on the album Shout at the Devil
 * "Dun Ringill" by Jethro Tull on the album Stormwatch
 * "In the Air Tonight" by Phil Collins on the album Face Value
 * "H." by Tool on the album Ænima
 * "The Pot" by Tool on the album 10,000 Days
 * "Strip My Mind" by Red Hot Chili Peppers on the album Stadium Arcadium
 * "I Am In Love With You" by Imogen Heap on the album Speak for Yourself
 * "The Happiest Days of Our Lives" by Pink Floyd on the album The Wall
 * "Alucard" by Gentle Giant on the album Gentle Giant
 * "Snowman" by XTC on the album English Settlement
 * "Feel Flows" by The Beach Boys on the album Surf's Up
 * "For The Love of Money" by The O'Jays on the album Ship Ahoy
 * "Blood" by Loop on the album A Gilded Eternity
 * "Who Feels Love?" by Oasis on the album Standing on the Shoulder of Giants
 * "Master's Apprentices" by Opeth on the album Deliverance

Use in other media
Reverse echo has also been used in film and television for an otherworldly effect on voices, especially in horror movies such as Poltergeist where it was used to suggest ghostly communication. The swelling effect has been used on environmental sounds and musical backgrounds to create tension and intensity, but can also be used for more subtle atmospheric effect.

Real-time digital reverse echo
Devices exist which offer an audio effect called "reverse echo" for use in live musical performances. This form of reverse echo immediately follows the initial source sound rather than preceding it as in tape-based or DAW-based reverse echo. Reverse echo devices sample a short section of the decay and sustain of a signal, reproducing it immediately in a way that starts small, quickly grows to a maximum then suddenly stops, making a strikingly unnatural sound. Real-time digital reverse echo became popular as pop, hair metal and New Wave music snare and cymbal effects in the 1980s; the effect still finds many uses today. Reverse echo was sometimes combined with a gated reverb effect for a wildly synthetic sound. Though most commonly heard on snare and cymbals, the effect can be employed on any signal or combinations of signals present in a performance. Digital reverse echo devices are available as guitar stomp boxes, outboard rackmount effects devices and as internal mixer effects on selected analog and digital mixers. Sampled emulations of reverse echo are found on many electronic percussion devices and sample libraries.