杏吧原创

From concert-hall designers to pop record producers, everyone in the music industry knows we love reverb. But why?

THE TALL, arched, windowless space has just enough light for me to make out the explicit frescoes of naked bodies and skeletons adorning its walls. But I鈥檓 not here in the suburbs of Oslo for the visuals. For people in my line of work, the (photo below) is most famous for its stunning acoustics.

I burst a balloon, and the bang takes 15 seconds to die away. I sing a note, and another and another, and they hang in the air together as a chord. The effect is spine-tingling. And although this is an extreme example, it illustrates a near-universal truth: we love our sounds with a bit of reverb.

This is, on the face of it, rather odd. Reverberation replaces the clear, unadulterated sounds of our own voices or instruments with something acoustically far more messy. Other musical preferences, such as why we choose consonance over dissonance, are well researched, but the question of why reverb is such an essential part of our musical experience has largely been met with silence. Time to make some noise.

(Image: Emanuel Vigeland Museum/Bono)

A first whisper of an explanation comes in the acoustic antithesis of Vigeland鈥檚 mausoleum: the in my lab at the University of Salford, UK. This is a sonically dead space, where every surface is covered with wedges of sound-absorbing foam. Playing my saxophone there isn鈥檛 a pleasant experience. Without sound bouncing back off the walls, it all sounds muffled and distant, I hear every mistake of my uneven breathing and nothing smooths the transition from one note to the next.

(Image: Raymond Gehman/National Geographic Creative)

Listening to a symphony in Vigeland鈥檚 reverberant mausoleum would hardly be a pleasant experience either, but too little reverb is a complaint made about many performance spaces. London鈥檚 Royal Festival Hall has attracted particular ire: the star conductor Simon Rattle once said of it that 鈥溾��. Orchestras today often face the challenge of playing music composed for baroque salons in halls filled with a couple of thousand concert goers and their sound-deadening clothing. A long reverberation time 鈥� defined as the time it takes for sound to decay by 60 decibels, or a factor of a million in intensity 鈥� allows musicians to fill such a large space. On opening in 1951, the Royal Festival Hall鈥檚 reverberation time was about 1.5 seconds: today, concert-hall architects aim for around 2 seconds.

鈥淎 long reverberation time allows musicians to fill a large space鈥�

(Image: Michael Kai/Corbis)

One functional reason for reverb, then, is to make musicians鈥� lives easier. But electronically added reverb is a common effect in studio-mixed rock and pop recordings. If it were all just about power output, the sound engineer could simply turn the volume knob up to 11. And you can鈥檛 hush things up by saying reverb helps musicians hear each other and keep in time and tune: even in live pop or rock performances, where musicians tend to monitor each other via headphones or nearby loudspeakers, preferred reverb times are between 0.6 and 1.2 seconds, according to .

Adelman-Larsen is a drummer, and provides one explanation from his experience of performing at a venue in one Danish town. 鈥淚t鈥檚 like playing in front of an aquarium,鈥� he says. 鈥淲e can see the audiences opening their mouths but we don鈥檛 hear much screaming.鈥� That might help to explain our love of reverb as audiences, too. Music-making probably evolved as a collaborative, social experience (see 鈥�Born to dance: The animals with natural rhythm鈥�); perhaps room reflections enable two-way communication between musicians and audiences, helping us to feel more part of the process even as passive listeners.

Studies of the brain鈥檚 response to vowel sounds show it has little influence on the neural encoding of pitch, indicating it doesn鈥檛 degrade our ability to follow melody. But it does degrade the encoding of harmonics, indicating a change in perception of timbre. My Salford colleague Bill Davies has floated the idea that reverberated speech acts like natural 鈥渟usurrating鈥� sounds, like those of a babbling brook, which have been shown to aid recovery from stress. Maybe our innate preference for natural things means we prefer music made less mechanistic by the random elements added by reverberation.

Another key word might be intimacy. Leaving loudness to one side, the emotional impact of music is known to increase the more listeners perceive themselves to be 鈥渟urrounded鈥� by it 鈥� a key effect of reverb that cinema sound engineers and concert-hall designers aim to harness. Research that involved playing listeners in a virtual-reality simulation while changing the room size has shown that non-threatening sounds, at least, are perceived to be more pleasant, calmer and safer in smaller rooms with an intimate reverb characteristic.

鈥淭he emotional impact of music is increased if we feel surrounded by it鈥�

Nicola Dibben of the University of Sheffield in the UK has used Adele鈥檚 Grammy award-winning 2011 hit Someone Like You as an example of how . On this track the piano is reproduced quietly, with natural reverberation making it sound relatively distant. The effect is to bring the singer鈥檚 voice closer to the listener, creating a sense that this is an intimate and authentic expression of the singer鈥檚 emotions.

This search for aural intimacy is an explanation that chimes with Linda-Ruth Salter, who has co-written a book on architecture and acoustic environments, 鈥� 鈥楧ry鈥� sounds are unnatural,鈥� she says. 鈥淓very sonic event occurs in a place, and those spatial enclosures modify the sound, including producing reverberation.鈥�

That starts me wondering whether our liking for reverb is innate at all. Could it be a preference we鈥檝e just learned because we rarely experience music without it? I don鈥檛 have a final answer yet, but it鈥檚 a question worth asking yourself, whether you are listening to festive carols in a cavernous cathedral or bopping to the synthetic sounds at the office party: why do we love acoustic fuzz so much?

This article appeared in print under the headline 鈥淩everb erb erb erb鈥�