Number of words – 491<\/p>\n\n\n\n
Sometimes everything that is needed cannot be made visible. Enter sound: sound can provide information available in no other way. Sound can tell us that things are working properly or that they need maintenance or repair. It can even save us from accidents. Consider the information provided by:<\/p>\n\n\n\n
\u2022 The click when the bolt on a door slides home<\/p>\n\n\n\n
\u2022 The tinny sound when a door doesn\u2019t shut right<\/p>\n\n\n\n
\u2022 The roaring sound when a car muffler gets a hole<\/p>\n\n\n\n
\u2022 The rattle when things aren\u2019t secured<\/p>\n\n\n\n
\u2022 The whistle of a teakettle when the water boils<\/p>\n\n\n\n
\u2022 The click when the toast pops up<\/p>\n\n\n\n
\u2022 The increase in pitch when a vacuum cleaner gets clogged<\/p>\n\n\n\n
\u2022 The indescribable change in sound when a complex piece of machinery starts to have problems<\/p>\n\n\n\n
Many devices simply beep and burp. These are not naturalistic sounds; they do not convey hidden information. When used properly, a beep can assure you that you\u2019ve pressed a button, but the sound is as annoying as informative. Sounds should be generated so as to give knowledge about the source. They should convey something about the actions that are taking place, actions that matter to the user but that would otherwise not be visible. The buzzes, clicks, and hums that you hear while a telephone call is being completed are one good example: take out those noises and you are less certain that the connection is being made.<\/p>\n\n\n\n
Real, natural sound is as essential as visual information because sound tells us about things we can\u2019t see, and it does so while our eyes are occupied elsewhere. Natural sounds reflect the complex interaction of natural objects: the way one part moves against another; the material of which the parts are made\u2014hollow or solid, metal or wood, soft or hard, rough or smooth. Sounds are generated when materials interact, and the sound tells us whether they are hitting, sliding, breaking, tearing, crumbling, or bouncing. Experienced mechanics can diagnosis the condition of machinery just by listening. When sounds are generated artificially, if intelligently created using a rich auditory spectrum, with care to provide the subtle cues that are informative without being annoying, they can be as useful as sounds in the real world.<\/p>\n\n\n\n
Sound is tricky. It can annoy and distract as easily as it can aid. Sounds that at one\u2019s first encounter are pleasant or cute easily become annoying rather than useful. One of the virtues of sounds is that they can be detected even when attention is applied elsewhere. But this virtue is also a deficit, for sounds are often intrusive. Sounds are difficult to keep private unless the intensity is low or earphones are used. This means both that neighbors may be annoyed and that others can monitor your activities. The use of sound to convey knowledge is a powerful and important idea, but still in its infancy.<\/p>\n\n\n\n