IELTS Listening · Cam 12

Test 4 Part 4

This lecture will be about the science of acoustics, The study of sound in relation to urban environments such as cities.

Level: C1 · 99 sentences

Transcript

  1. This lecture will be about the science of acoustics,
  2. The study of sound in relation to urban environments such as cities.
  3. As an acoustic engineer myself,
  4. I think this is an area
  5. Where we're likely to see great changes.
  6. In the past, researching urban soundscapes was simple.
  7. We measured levels of sound in decibels
  8. So I used to take my sound meter
  9. And I measured the noise somewhere
  10. And then I might ask a sample
  11. Of people to say at what level the sound became annoying
  12. With data like this acoustic engineers have been able to build up
  13. What we call noise maps maps of the sound environment
  14. But actually these aren't a lot of use
  15. What they do show is that the highest
  16. Noise levels are generally on roads.
  17. Well, that's not really very surprising.
  18. But there's quite a lot going on that these maps don't show,
  19. Because they can't capture the complex way that sound varies over time.
  20. So they ignore important issues such
  21. As the noise someone might hear
  22. From the open windows or gardens of their neighbours.
  23. And this sort of noise can be quite significant in summer.
  24. We don't have any databases on this sort of information.
  25. As well as that,
  26. These records of sound levels take no account of the fact
  27. That people vary in their perceptions of noise.
  28. So someone like me with years of working in acoustics
  29. Might be very different from you in that regard.
  30. But anyway, even though these noise maps are fairly crude,
  31. They've been useful in providing information and raising awareness that noise matters.
  32. We need to deal with it, and so it's a political matter.
  33. And that's important.
  34. We need rules and regulations because noise
  35. Can cause all sorts of problems.
  36. Those of you who are city
  37. Dwellers know that things go on 24 hours a day,
  38. So city dwellers often suffer from interrupted sleep.
  39. It's also known that noise can lead
  40. To a rise in levels of stress
  41. Due to physical changes in the body
  42. Affecting the composition of the blood.
  43. And there are other problems as well.
  44. For instance, if school children don't have a quiet place to study,
  45. Their work will suffer.
  46. Now one problem with decibel measurement
  47. Is that it doesn't differentiate between different types of noise.
  48. Some types of sounds that most
  49. People would probably think of as nice and relaxing
  50. Might well score quite highly in decibel levels.
  51. Think of the sound made by a fountain
  52. In a town square, for example.
  53. That's not necessarily something that we'd want to control or reduce.
  54. So maybe researchers should consider these sorts of sounds in urban design.
  55. This is going to be tricky,
  56. Because just measuring decibel levels isn't going to help us here.
  57. Instead, many researchers are using social science techniques,
  58. Studying people's emotional response to sound by using questionnaires and so on.
  59. So what exactly do people want to hear in an urban environment?
  60. Some recent interdisciplinary research has come
  61. Out with results that at first sight seem contradictory.
  62. A city needs to have a sense of activity.
  63. So it needs to be lively,
  64. With sounds like the clack of high
  65. Heels on a pavement or the hiss of a coffee machine.
  66. But these mustn't be too intrusive,
  67. Because at the same time we need to be able to relax.
  68. One of the major problems in achieving this
  69. Will be getting architects and town planners to use the research.
  70. Apart from studying the basics of acoustics,
  71. These people receive very little training in this area.
  72. They should be regarding sound as an opportunity
  73. To add to the experience of urban living,
  74. Whereas at present they tend to see it
  75. As something to be avoided or reduced as far as possible,
  76. Or something that's just a job
  77. For engineers, like the street drainage system.
  78. What's needed is for noise in cities
  79. To be regarded as an aesthetic quality,
  80. As something that has the qualities of an art form.
  81. If we acknowledge this,
  82. Then we urgently need to know what governs it,
  83. And how designers can work with it.
  84. We need to develop a complex understanding of many factors.
  85. What is the relationship between sound and culture?
  86. What can we learn from disciplines such
  87. As psychology about the way that sound
  88. Interacts with human development and social relationships,
  89. And the way that sound affects our thoughts and feelings?
  90. Can we learn anything from physics about the nature of sound itself?
  91. Today's powerful technologies can also help us.
  92. To show us their ideas and help
  93. Us to imagine the effect their buildings will have,
  94. Architects and town planners already use virtual reality.
  95. But these programs are silent.
  96. In the future, such programs could use realistic sounds,
  97. Meaning that soundscapes could be explored before being built.
  98. So hopefully, using the best technology we can lay our hands on,
  99. Will be a pleasure to the ears as well as the eyes.