Innovations in cell phones

In the 1980s Amar Bose, an electrical engi­neer at the Massachusetts institute of tech­nology and founder of the audio company of that name, pulled off this trick for the first time by designing pilots’ headphones that reduce the noise of jet engines. Now, retail versions of such noise-cancelling headsets are a favourite with passengers, too, and the technology is spreading.

The closer to the ear the microphone is located, the simpler the process becomes. For that, the smaller the microphone is, the better. Small mikes are easier to fit into ear­pieces, and recently they have been getting very small indeed. Jeremie Bouchaud and his colleagues at the German office of iSuppli, a market-research company that has been analyzing the sector, are increasingly finding a new sort of tiny microphone in the products which they tear apart in order to identify manufacturing trends.

These mikes use a technology known as MEMS (micro electro mechanical sys­tems). A silicon membrane is fabricated over a tiny cavity. This allows it to vibrate in sympathy with sound waves, like the di­aphragm in a conventional microphone. The vibrations change the electrical prop­erties of the device and this electrical sig­nal is converted into an audio signal. One of the smallest MEMS microphones found by iSuppli is a device just over 1 mm thick. It is fitted into the latest version of Apple’s ul­tra-slim iPod Nano to record sound for its video camera.

One mike, however, is often not enough, Mr Bouchaud is finding more than one MEMS microphone inside ever more of the products he disassembles, and these extra mikes are often being used to add noise-cancelling features. Two of the newest mobile phones, Google’s Nexus One and Motorola’s Droid, both use MEMS microphones in this way. Mr Bouchaud expects this feature will be incorporated into more products. Indeed, last year, Knowles Acoustics of Itasca, Illinois, which has been making MEMS microphones since 2003, became the first manufacturer to have shipped a billion of the devices.

Nokia has been working with Wolfson microelectronics of Edinburgh to produce a wireless headset for mobile phones and music players that uses ten MEMS micro­phones: two to record speech and eight to cancel noise. Sony has new noise-cancel­ling earbud-type headphones that use MEMs technoly. It claims these can elim­inate more than 90% of background noise. The earbuds have three separate settings: one for planes, one for trains and buses, and one for general office hubbub.

Other uses are emerging. Akustica, based in Pittsburgh, Pennsylvania, puts a MEMs microphone complete with the cir­cuitry needed for digital output into a package less than 5mm square. Digital out­put helps protect against radio and electro­magnetic interference, which can cause audio problems with microphones mounted on computer displays. It also al­lows for elaborate signal processing.

Using more than one microphone im­proves sound quality. Microsoft, for exam­ple, has been developing software that takes advantage of the different times an acoustic wave arrives at each microphone in an array around the screen of a comput­er. By analyzing these signals the software is able to make the array work like a direc­tional microphone. In effect it turns an electronic ear towards someone who is speaking – when communicating with Skype, say – and thus suppresses back­ground noises. That should mean that there is no longer any reason for people to shout at their computers, either.

(“The Economist”, February 13^th 2010, page 79)

Exercise 8. Comprehension check. Answer the following questions:

1. What kind of headsets is favourite with passengers?

2. How is Jeremie Bouchaud conducting his research of manufacturing trends?

3. What does MEMs stand for?

4. What is the size of the smallest MEMs microphones found by iSuppli?

5. What large companies use MEMs technology in their products?

6. How many separate settings do the earbuds have?

7. What is the function of digital output?

8. Where does an electronic ear turn towards?

Exercise 9. Translate the following sentences into English using the target vocabulary (Exercises 3 and 6):

1. Моя головная боль является неизбежным последствием постоянного шума в офисе.

2. Главным достоинством новой серии телефонов этой фирмы является великолепные шумоподавляющие характеристики.

3. Настройки данного музыкального центра очень просты.

4. Ребенок разобрал игрушку на крошечные детали.

5. Фоновые шумы не позволили мне хорошо слышать моего собеседника, его голос то исчезал, то появлялся вновь, и, в конце концов, связь прервалась.

Exercise 10. Paraphrase the following sentences using the target vocabulary (Exercises 3 and 6):

1. We support new production tendencies aimed at liquidating drawbacks revealed last year at the plant.

2. Do not speak loud, your headache cannot justify your unbearable behavior.

3. I do not like my neighbour as he is constantly boasting to attract attention.

4. If we choose freedom of speech, we should not let the authorities prevent our meetings.

Speaking

Exercise 11. Work in pairs. Discuss different types of noise that irritate you most of all, make a list of noisy situations and places that might be dangerous for human health or prevent you from performing efficient work and offer effective ways to reduce them or protect yourself from noise. Make use of your target vocabulary (Exercises 3 and 6). Compare your results with the results of the rest of the group.

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