58.16 Headset design criteria

First and foremost it must be comfortable. If it is required to be worn for long periods, then weight is vital too. There are few headsets which can be tolerated continuously over an eight hour day. So it is essential to know the shift period that the user will work.

Its design must be attractive to the user.

Does the user have to move around the telephone point in doing the job? If so, a quick-release connector is essential: it also reduces wear and tear on the terminal plug.

Monaural receivers work well when the user needs to listen in two places at once, e.g. a front desk receptionist/telephonist. Binaural receivers help shut out background noise.

Is there a need for split listening? e.g. radio in one ear, telephone in the other, with the ability to switch the microphone from one to the other.

Boom-mounted microphones are better than acoustic tubes and essential in noisy environments.

Under-the-chin headsets don't disturb the hair. Over-the-head style headsets are stable and more robust. Contour 'on-the-ear' style headsets are light, less noticeable. Conversion kits are an important new cost development and allow users to experiment with both over-the-head and on-the-ear styles to decide their preferences. Over-the-ear pads are comfortable, won't cause infection and block out some external sound. In-the-еаг tips offer high close acoustic coupling. Some people find the tips uncomfortable, irritating and unhygienic.

The environment is all important. In hot climates, ears sweat. Vinyl ear pads can be wiped clean with a sterilising pad, while foam pads absorb perspiration and need replacing regularly.

Is the office noisy? Does it lack acoustic damping, are the surfaces hard, is there a lot of paper shuffling? In particularly noisy environ­ments, noise cancelling microphones are available but they must be positioned properly for optimum performance. If not, their use can be counter productive.

Automatic Gain Control (AGC) on the microphone circuit cuts the gain when the user is not talking. A manual gain control on the headset allows adjustment to suit line conditions and the speech level of individual callers. A thumbwheel control is usually preferred to a switchable control. Preferably this should provide for -3dB to +12dB gain adjustment.

Modular design eases logistics for maintenance purposes.

After sales service is vitally important. Headsets are fragile and an efficient and speedy after-sales back-up is essential to most users.

1 Learn the words & word combinations:

Group listening	Групповое прослушивание
Call monitoring	(текущий) контроль за соединением (в сети)
Loudspeaking telephones	Громкоговорящий телефонный аппарат, телефонный аппарат с громкоговорителем
Monitor amplifier	Усилитель контроля (звукозаписи или воспроизведения)
Handsfree telephone	Громкоговорящий телефонный аппарат
Acoustic feedback	Акустическая обратная связь
Howling	акустическая обратная связь микрофонный эффект
Attenuator	Аттенюатор
PBX (private branch exchange)	телефонная станция для частного пользования учрежденческая телефонная станция с исходящей и входящей связью с городом
Sound emanation	Выделение звука, эманация
Link access procedure	Процедура доступа к каналу (связи)
Stimulus	Управляющее воздействие, задающее воздействие
Of paramount importance	Первостепенной важности
Transducer	Преобразователь
Automatic gain control	Автоматическая регулировка усиления
Adjustable volume control	Регулируемый уровень громкости
Electret	Электрет
Boom	Микрофонный штатив
Noise canceling microphone	Микрофон с шумоподавлением
Pressure gradient	Градиент давления
Sound ports	Звуковые порты
Frequency response	АЧХ, амплитудно-частотная характеристика
Directional characteristic	Характеристика направленности
Attenuation	Затухание, ослабление
Polar form	Тригонометрическое представление
Dampen	Демприровать, гасить (колебания)
Gain output	коэффициент отдачи универсальность, разносторонность
Versatility	Гибкость в применении
OEM (original equipment manufacturer)	(фирма) изготовитель комплексного оборудования
Rectifier	Выпрямитель
Monaural receivers	Моноуральные приёмники

2. Write out the words and word combinations which are still unknown to you and learn them.

3. Read and translate the text 11 – 16

4. Put five – seven questions to this part of the text