The Sound Book: The Science of the Sonic Wonders of the World (37 page)

At my university, the anechoic chamber wows visitors because the silence allows them to listen to their hearts and minds. I have always thought it would be good to have one in a shopping mall so that more of the public could experience the silence. I think it would also be fun to make one with transparent walls; at least one concert hall has been built with huge glass walls, so why not an anechoic chamber? To do this, the foam wedges that cover every interior surface of a conventional design would have to be replaced with transparent absorbers. There has been a lot of interest in transparent acoustic treatments lately because they fit with the trend in architecture for lots of glazing. They can be made from perforated plastic, a bit like the rustling plastic bags that warm bread used to be sold in. They are not perfect at removing sound, but by curving the walls of a see-through anechoic chamber, like the bottom half of a goldfish bowl, any reflected sound could be directed up above the head of the listeners. In this room you could take a break from the city in complete silence, while others walk by laden with shopping bags.

For me, the more conventional anechoic chamber at Salford University has become a normal room for scientific experimentation, partly because of my brain's automatic habituation to the acoustic, but also because I took it for granted. I started collecting sonic wonders because I realized I needed to rediscover the skill of listening. In an effort to awaken my ears, I went on soundwalks, participated in a silent retreat, and floated about in brine. Along the way I have had the chance to interview inspiring artists, sound recordists, and musicians who have demonstrated enviable sensitivity and understanding of the aural. They taught me so much, and made me realize that scientists and engineers need to listen more to them and to the world around us. I hope all of us will open our ears to the strange sounds around us. As my search draws to an end, I realize that I have changed. If we all listened to and cared for the sonic wonders around us, as I now try to do, we would start to build a better-sounding world.

It has been a privilege to discuss acoustics with many great people over the last twenty-five years. I would like to thank the following, who, for this book, explained acoustic phenomena to me or helped me to gain new sound experiences: Keith Attenborough; Mark Avis; Michael Babcock; Barry Blesser; David Bowen; Stuart Bradley; Andrew Brookes; Angus Carlyle; Mike Caviezel; Dominic Chennell; Rob Connetta; Frances Crow; Marc Crunelle; John Culling; Peter Cusack; Helen Czerski; Peter D'Antonio; Bill Davies; Charles Deenen; Stéphane Douady; John Drever; Bruno Fazenda; Linda Gedemer; Tim Gedemer; Tony Gibbs; Wendy Hasenkamp; Marc Holderied; Diane Hope; Seth Horowitz; Simon Jackson; Brian Katz; Paul Kendrick; Allan Kilpatrick; Tim Leighton; Jane MacGregor; Katherine MacLean; Paul Malpas; Barry Marshall; Henric Mattsson; Bryony McIntyre; Daniel Mennill; Andy Moorhouse; Myron Nettinga; Stuart Nolan; James Pask; Lee Patterson; Chris Plack; Eleanor Ratcliffe; Brian Rife; John Roesch; Duncan from the Royal Society for the Protection of Birds (RSPB); Martin Schaffert; Ann Scibelli; Clare Sefton; Jonathan Sheaffer; Bridget Shield; Matt Stephenson; Davide Tidoni; Rupert Til; Lamberto Tronchin; Rami Tzabar; Nathalie Vriend; Chris Watson; Nick Whitaker; Andrew Whitehouse; Heather Whitney; Pascal Wyse; Luray Caverns; members of Subterranea Britannica; the teachers, coordinators, fellow retreatants, and staff at the Buddhist retreat; and anyone else I accidentally left off this list.

I thank the Engineering and Physical Sciences Research Council for my Senior Media Fellowship, which gave me the time to develop the proposal for this book. Also many have helped me to develop as a science communicator, including staff at the BBC Radio Science Unit and
New Scientist
.

My agent, editors, and copy editor have been highly influential in shaping the overall narrative of this book and improving the writing. I'm indebted to Stephanie Hiebert, Tom Mayer, Zoë Pagnamenta, Kay Peddle, Peter Tallack, and Gemma Wain.

Thank you to Nathan Cox, who helped with some of the diagrams. Finally, thanks to the following, who commented on early drafts: Deborah, Jenny, Peter, and Stephen Cox.

1 M. Spring, “Bexley Academy: Qualified Success,”
Building
, June 12, 2008.

2
The New Yorker
described
The Phantom Tollbooth
as the “closest thing that American literature has to an ‘Alice in Wonderland.' ” A. Gopnik, “Broken Kingdom: Fifty Years of the ‘Phantom Tollbooth,' ”
New Yorker
, October 17, 2011, http://www.newyorker.com/reporting/2011/10/17/111017fa_fact_gopnik.

3 British Library Sounds, “Programme II: B—Part 1: Listening. Soundscapes of Canada,” http://sounds.bl.uk/View.aspx?item=027M-W1CDR0001255-0200V0.xml, accessed October 6, 2011.

4 R. M. Schafer,
The Soundscape: Our Sonic Environment and the Tuning of the World
(Rochester, VT: Destiny Books, 1994), 208.

5 Bill Davies, personal communication, September 2011.

6 C. Spence and V. Santangelo, “Auditory Attention,” in
The Oxford Handbook of Auditory Science: Hearing
, ed. C. J. Plack (Oxford: Oxford University Press, 2010). When not writing about auditory attention, Charles Spence researches how sound affects taste.

7 Switching talkers works only if both speakers are the same gender.

8 UK data from MORI Social Research Institute:
Neighbour Noise: Public Opinion Research to Assess Its Nature, Extent and Significance
(Department for Environment, Food and Rural Affairs, 2003). US data from the 2000 US census as reported in L. Goines and L. Hagler, “Noise Pollution: A Modern Plague,”
Southern Medical Journal
100 (2007): 287–94. EU data from
Future Noise Policy
, European Commission Green Paper, COM (96) 540 final (Brussels: Commission of the European Communities, 1996).

9 V. J. Rideout, U. G. Foehr, and D. F. Roberts,
Generation M
2
: Media in the Lives of
8
- to
18
-Year-Olds
(Menlo Park, CA: Kaiser Family Foundation, 2010).

10 The quote is from Mike Caviezel (personal communication, May 13, 2011), whose experiences are given in full later in the book.

11 R. Campbell-Johnston, “Hockney Works Speak of Rapture,”
Times
(London), January 21, 2012.

1 A. Tajadura-Jiménez, P. Larsson, A. Väljamäe, D. Västfjäll, and M. Kleiner, “When Room Size Matters: Acoustic Influences on Emotional Responses to Sounds,”
Emotion
10 (2010): 416–22.

2
Encyclopaedia Britannica
, “Wallace Clement Sabine,” http://www.britannica.com/EBchecked/topic/515073/Wallace-Clement-Sabine, accessed May 30, 2013.

3 W. C. Sabine, “Architectural Acoustics: Correction of Acoustical Difficulties,”
Architectural Quarterly of Harvard University
, March 1912.

4 R. T. Beyer,
Sounds of Our Times: Two Hundred Years of Acoustics
(New York: Springer, 1998). Original appeared in H. Matthews,
Observations on Sound
(publisher unknown, 1826).

5 The physical volume might be altered as well. In designing a concert hall for classical music, at least 10 cubic meters (350 cubic feet) per seat is a useful rule of thumb.

6 This quote comes from 1972, just before the lecture hall was improved by further renovations. B. F. G. Katz and E. A. Wetherill, “Fogg Art Museum . . . Room Acoustics” (paper presented at Forum Acusticum, Budapest, Hungary, August 29–September 2, 2005). The hall was demolished in 1973 to make way for student accommodation.

7 The value is for a full audience at midfrequency.

8 The quote comes from L. L. Beranek,
Music, Acoustics & Architecture
(Hunting, NY: Krieger, 1979), which includes a wonderful first chapter detailing some of the myths of concert hall acoustics.

9 P. Doyle,
Echo and Reverb: Fabricating Space in Popular Music,
1900
–
1960 (Middletown, CT: Wesleyan University Press), 143.

10 M. Barron,
Auditorium Acoustics and Architectural Design
, 2nd ed. (London: Spon Press/Taylor & Francis, 2010), 103.

11 G. A. Soulodre, “Can Reproduced Sound Be Evaluated Using Measures Designed for Concert Halls?” (paper presented at Spatial Audio & Sensory Evaluation Techniques Workshop, Guildford, UK, April 6–7, 2006).

12
All My Children
was a soap opera that appeared on ABC for forty-one years. The quote is from J. C. Jaffe,
The Acoustics of Performance Halls
(New York: W. W. Norton, 2010).

13 Other changes also affected the acoustics. See L. L. Beranek, “Seeking Concert Hall Acoustics,”
IEEE Signal Processing Magazine
, 24 (2007): 126–30.

14 Ibid.

15 Loudness is also important for this effect. As an orchestra plays louder, for example, the envelopment and broadening increase.

16 Brian Eno, speaking on the BBC Radio 4 program
Acoustic Shadows
, broadcast September 14, 2004.

17 This quote comes from
Concert Hall Acoustics: Art and Science
, a 2001 exhibit at the South Bank Centre, London. Source unknown.

18 L. L. Beranek,
Concert Halls and Opera Houses
, 2nd ed. (New York: Springer, 2004), 7–8.

19 Barron,
Auditorium Acoustics
, 153.

20 S. Quinn, “Rattle Plea for Bankrupt Orchestras,”
Guardian
(London), July 13, 1999.

21 D. Trevor-Jones, “Hope Bagenal and the Royal Festival Hall,”
Acoustics Bulletin
26 (May 2011): 18–21.

22 It was an underestimation of the audience absorption that is mostly to blame for the lack of reverberance in the hall; see B. M. Shield, “The Acoustics of the Royal Festival Hall,”
Acoustics Bulletin
26 (May 2011): 12–17.

23 R. A. Laws and R. M. Laws, “Assisted Resonance and Peter Parkin,”
Acoustics Bulletin
26 (May 2011): 22–29.

24 I found reverberation time values for the Taj Mahal on the web, with figures ranging from 10 to 30 seconds, but I could not find a reliable source. Similarly, there are references to a reverberation time of 20 seconds for Gol Gumbaz, but no information to check the provenance of the number.

25 Tor Halmrast, personal communication, October 3, 2011.

26 This reverberation time comes from A. Buen, “How Dry Do the Recordings for Auralization Need to Be?”
Proceedings of the
Institute of Acoustics
30 (2008): 108; it was recorded when there were twenty-five people in the room. A better value for the empty room at midfrequency is about 11 seconds, estimated using an impulse response from the software Altiverb.

27 Or one needs to use a measure such as reverberation time, which does not depend on the loudness of the initial sound.

28 The poem is from Hilaire Belloc's
Cautionary Tales for Children
, first published in 1907, and begins, “A trick that everyone abhors, / In little girls is slamming doors.” Rebecca gets her comeuppance when a bust falls from above a door and kills her.

29 For the audio geeks out there, this is an average of the 500-, 1,000-, and 2,000-hertz octave bands. The calculation is based on measurement data from Damian Murphy from the University of York (http://www.openairlib.net/auralizationdb/content/hamilton-mausoleum, accessed July 15, 2012) because there were too many people in the room (who absorb sound) when I was visiting.

30 See P. Darlington, “Modern Loudspeaker Technology Meets the Medieval Church,”
Proceedings of the Institute of Acoustics
, 2002; or the modestly titled paper by D. Lubman and B. H. Kiser, “The History of Western Civilization Told through the Acoustics of Its Worship Spaces” (paper presented at the 19th International Congress on Acoustics, Madrid, September 2–7, 2007).

31 R. C. Rath, “Acoustics and Social Order in Early America,” in
Hearing History: A Reader
, ed. M. M. Smith (Athens: University of Georgia Press, 2004), 209.

32 This estimate is based on Barron,
Auditorium Acoustics
, 19.

33 S. J. van Wijngaarden and R. Drullman, “Binaural Intelligibility Prediction Based on the Speech Transmission Index,”
Journal of the Acoustical Soc
iety of America
123 (2008): 4514–23. The phenomenon is similar to what happens with the cocktail party effect, that magical process that enables us to pick out the sound of a single speaker from the hubbub of the rest of a party.

34 Even if the priest is not straight ahead, these are ways for the brain to exploit this binaural processing.

35 For a nonecclesiastical example, see H. M. Goddard, “Achieving Speech Intelligibility at Paddington Station,”
J
ournal of the Acoustical Society of America
112 (2002): 2418. The acoustic principles are the same.

36 P. F. Smith,
The Dynamics of Delight: Architecture and Aesthetics
(London: Routledge, 2003), 21.

37 Beranek, Concert Halls and Opera Houses, 9. Incidentally, Richard Wagner was an example of a composer becoming a successful acoustician when he helped design the Bayreuth Festival Theatre in 1876. The innovative orchestral pit had space for up to 130 players and extended deep under the stage. Since there is no direct line of sight between orchestra and audience, much of the treble sound is lost. In addition to creating the distinctive subdued, haunting Wagner sound, this arrangement enables the singers to be heard above a large orchestra.

38 T. H. Lewers and J. S. Anderson, “Some Acoustical Properties of St. Paul's Cathedral, London,”
Journal of Sound and
Vibration
92 (1984): 285–97.

39 F. Jabr, “Gunshot Echoes Used to Map Caves' Interior,”
New Scientist
, no. 2815 (June 9, 2011): 26.