IntroductionReverberations are everywhere around us, in fact, there is likely no natural space on planet earth that doesn’t have some level of reverberation taking place in it(were a sound to be produced in it)Yet it is a phenomenon that is paid little mind and is often taken for granted by musician and non-musician alike. After all its around us, all day, every day, much like oxygen is. For this reason, the non-musician can be forgiven for paying this phenomena little mind, the musician, on the other hand, cannot be forgiven so easily and does so at their own peril. Reverberations and other sound reflection phenomena undeniably play an integral part in shaping sounds produced by musical instruments. For example, a great performer, performing in a poorly built auditorium will not be as impactful as they would be in a well built one, I dare say their personal performance may very well be affected as well. If a student makes a recording in a room that is wrong for their instrument, it could be mean the difference between getting to the second round of a competition or not. What I am trying to convey here is that a room can make or break a performance and or recording. It is therefore important to have some level of understanding in how a room can shape the sound of an instrument. Even a rudimentary understanding can help a musician make the right adjustments. Even if it means simply putting up a blanket, or standing off centre in a square room.What is Reverb?Reverberation or reverb for short can be described as the reflection (bouncing) of sound waves off of surfaces and objects, in any room, space or environment. The result of these reflections is an audible prolonging of the sound being produced, and arises due to the delay times of the reflections between the direct and reflected sound waves.A Reverberation is created when a reflected sound wave takes 0.1 second or less to return to your ears.If a sound wave takes over 0.1 seconds to travel back to your ears after being reflected, then it is technically not reverb, but instead becomes an echo.(strictly speaking)How Surfaces and Objects Affect Reverberation?The manner in which a sound wave is reflected and altered depends on the characteristics of the objects and surfaces in that environment.For example, hard materials like wood and brick tend to reflect more sound waves than soft materials, rough surfaces tend to diffuse sound more than smooth surfaces and concave surfaces tend to amplify sound waves more than flat surfaces. Studio builders and recording engineers use these facts to create “live rooms”(rooms made of hard reflecting materials) and “dead rooms”(rooms made of soft sound absorbing materials).Tip: For a less hollow reverberant sound opt for a smaller room, with the microphone closer to the instrument. If the room is too reverberant, try hanging up a folded up blanket on the surface behind you and behind the recording device. Also, avoid recording in rooms that are asymmetrical or close to a symmetrical square. Therefore the types of surfaces and objects in an environment and even the shape of the environment have a direct effect on how a sound is reflected, which in turn affects the acoustic and timbral quality of the sound. This is the reason why some rooms or spaces sound better for recording certain instruments vs others.*Note: An extreme example of a dead room is an anechoic chamber (meaning echo-free). These types of rooms are specially designed to absorb all acoustic reflections. The result is a room that is so free of acoustic reflections, that it is said you can hear the flow of your blood, and even pulsing of your own heart when you are inside and the doors are closed. A Brief HistoryNatural room ambience has always been a feature of recorded music, however, it wasn’t until the creation of artificial reverb in the late 1930s that recording engineers were able to alter and control sounds of the space that the instruments were recorded in. With improving technologies and a better understanding of acoustics, recording engineers began experimenting with techniques to create artificial reverb, with the aim of getting better control over the ambient qualities of their instrument recordings. Although these early techniques are referred to as “false” reverberation, they actually seem more natural when compared to the types of reverb more commonly used in today’s recordings.Chamber Reverb The first artificial reverb was called “Chamber Reverb” or sometimes called Room or Hall reverb. This type of reverberation was created by playing a “dry” pre-recorded sound through a loudspeaker in the room or hall of choice. The sound coming through the loudspeaker was then recorded by a microphone on the other side of the room. This new “wet” signal could then be mixed with the dry one, resulting in a more ambient recording, that sounded like it was recorded in an entirely different space than it actually was. Chamber Reverb remained a staple of recordings after its creation and was famously used on many hit records. Some recording studios like Abbey Road and Motown went as far as building purpose-built reverb and echo chambers. This method, although less common today is still used to some degree, as it provides a unique realness and ambience to audio recordings.Plate and Spring ReverbOver time, companies like Elektro-Mess-Technik (EMT) would create truly artificial reverb units that also happened to be portable. These new reverberation units came in the form of plate and spring reverb. The first of these reverb units was the EMT140 Reverberation Unit-a plate reverb, and it was released in 1957. Both plate and spring reverb are electromechanical technologies, these types of reverb are artificial in every sense of the word and work by passing a “dry” audio signal through a metal plate or spring (via a transducer).The resulting vibrations are then picked up on the other end of the plate or spring with one or two pickups (mono or stereo). The amount of reverberation in the plate can be controlled with a dampening pad. This new “wet” reverberant signal can then be mixed with the dry signal, giving the new audio a distinctive and unique reverberant acoustic quality, quite different from the reverb created using the earlier and more natural Chamber technique.Tip: Small Plate reverbs are especially useful on drums and other percussive instruments, especially when you don’t want an obvious overbearing reverberation on dry instruments. Spring reverbs are useful on many instruments, but especially instruments with long release and sustain times, like guitars.*Note: Although more “portable” than a Cathedral, plate reverbs tended to be much larger than their spring counterparts(100Kg+), therefore the plate reverb was almost always reserved for the recording studio, while spring reverbs found their way into guitar amps, cars and other audio devices, due to their much smaller size.Digital ReverbIn 1976 EMT changed the music production scene once again by releasing what is considered the worlds first digital reverb unit, the EMT 250. Digital reverbs were different from previous types of reverb, because they gave the user much more control, by running algorithms that allowed for the adjustment of various other attributes, like early reflections and delay times. Such features were simply not present on previous reverb units.This meant that the user could now emulate real-world spaces, as well create complex and completely unnatural sounding reverberations. In addition to this, the EMT 250 was also the worlds first multi-processing unit, incorporating effects such as echo, phase and chorus into its features, which at the time was a major innovation.To this day the EMT 250 is a highly praised and sought after reverb unit, with some people even labelling it one of the “best reverb units ever made”.Convolution ReverbDigital reverb stepped into new territories once again in 1999 when Sony unveiled the DRE S777-the first real-time convolution reverb. This was special because convolution reverb allowed the user to create reasonably convincing samples of real-world spaces (impulse responses). Meaning that producers/engineers could now accurately emulate the ambient qualities of world-renowned spaces and environments such as rooms at Abbey Road, Sunset Records, Rosslyn Chapel or even in the Grand Canyon. Or on a less grandiose scale, they could even capture and use the reverberant qualities of their home bathrooms.This is not to say that using a convolution reverb automatically made your recordings perfect, but it allowed you to put your instruments in almost any room or space on the planet, as long as the impulse response of that space had been created recorded and saved into the sample bank.Conclusion Plate, Spring, Chamber and Convolution reverbs are all still in use today. However, over time these reverb units have been emulated and made available as digital software plugins, otherwise known as Virtual Studio Technology or VSTs. The conversion of these hardware units to software has not only made them more affordable for the average music producer but has also allowed software programmers to add more parameters of control to emulations of plate and spring reverb units. Creating new possibilities and adding something new to these old versions of reverb.These innovations have given audio engineers/music producers everywhere more choice, by allowing them the opportunity to immerse their instrumentation and recordings in world-renowned spaces and environments. Or to use emulations of the age-old tried and tested units. Or to create complex and out of this world, sound pallets and sonic environments.