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Echo Cancellation
Echo suppression and echo cancellation are methods used in telephony to improve voice quality by preventing echo from being created or removing it after it is already present. In addition to improving subjective audio quality, echo suppression increases the capacity achieved through silence suppression by preventing echo from traveling across a telecommunications network. Echo suppressors were developed in the 1950s in response to the first use of satellites for telecommunications. Echo suppression and cancellation methods are commonly called acoustic echo suppression (AES) and acoustic echo cancellation (AEC), and more rarely line echo cancellation (LEC). In some cases, these terms are more precise, as there are various types and causes of echo with unique characteristics, including acoustic echo (sounds from a loudspeaker being reflected and recorded by a microphone, which can vary substantially over time) and line echo (electrical impulses caused by, e.g., coupling between t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephony
Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunication services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is intimately linked to the invention and development of the telephone. Telephony is commonly referred to as the construction or operation of telephones and telephonic systems and as a system of telecommunications in which telephonic equipment is employed in the transmission of speech or other sound between points, with or without the use of wires. The term is also used frequently to refer to computer hardware, software, and computer network systems, that perform functions traditionally performed by telephone equipment. In this context the technology is specifically referred to as Internet telephony, or voice over Internet Protocol (VoIP). Overview The first telephones were connected directly in pairs. Each user had a separate telephone wire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voice Engine
A voice engine is a software subsystem for bidirectional audio communication, typically used as part of a telecommunications system to simulate a telephone. It functions like a data pump for audio data, specifically voice data. The voice engine is typically used in an embedded system. The term became popularized after 2000 with the proliferation of voice over internet protocol technology in software DSP systems. Voice engines handle the voice processing for an IP Phone system on a standard processor, compared to prior generations of systems which required dedicated, math-optimized digital signal processor chips. Voice engines are highly optimized software subsystems due to the mathematically complex signal processing required for voice filtering and speech coding. The filter stages and coding elements within a voice engine are designed to work in conjunction with a larger telecommunications system, including only a specific and limited range of processing to minimize the voic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interactive Voice Response
Interactive voice response (IVR) is a technology that allows telephone users to interact with a computer-operated telephone system through the use of voice and DTMF tones input with a keypad. In telecommunications, IVR allows customers to interact with a company's host system via a telephone keypad or by speech recognition, after which services can be inquired about through the IVR dialogue. IVR systems can respond with pre-recorded or dynamically generated audio to further direct users on how to proceed. IVR systems deployed in the network are sized to handle large call volumes and also used for outbound calling as IVR systems are more intelligent than many predictive dialer systems. IVR systems can be used standing alone to create self-service solutions for mobile purchases, banking payments, services, retail orders, utilities, travel information and weather conditions. In combination with systems such an automated attendant and ACD, call routing can be optimized for a better ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smart Speakers
A smart speaker is a type of loudspeaker and voice command device with an integrated virtual assistant that offers interactive actions and hands-free activation with the help of one "hot word" (or several "hot words"). Some smart speakers can also act as a smart device that utilizes Wi-Fi, Bluetooth and other protocol standards to extend usage beyond audio playback, such as to control home automation devices. This can include, but is not limited to, features such as compatibility across a number of services and platforms, peer-to-peer connection through mesh networking, virtual assistants, and others. Each can have its own designated interface and features in-house, usually launched or controlled via application or home automation software. Some smart speakers also include a screen to show the user a visual response. As of winter 2017, it is estimated by NPR and Edison Research that 39 million Americans (16% of the population over 18) own a smart speaker. A smart speaker with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Handset
A handset is a component of a telephone that a user holds to the ear and mouth to receive audio through the receiver and speak to the remote party using the built-in transmitter. In earlier telephones, the transmitter was mounted directly on the telephone itself, which was attached to a wall at a convenient height or placed on a desk or table. Until the advent of the cordless telephone, the handset was usually wired to the base unit, typically by a flexible tinsel wire. The handset of a cordless telephone contains a radio transceiver which relays communication via a base station that is wired to the telephone line. A mobile phone does not require a base station and communicates directly with a cell site in designated frequency bands. Handset symbol A graphic symbol that designates a handset is used on cordless and mobile phones to specify placing or ending a telephone call. Usually a button with green upright (off-hook) handset icon is used for starting a call, and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or "loudspeaker", comprises one or more such speaker ''drivers'', an enclosure, and electrical connections possibly including a crossover network. The speaker driver can be viewed as a linear motor attached to a diaphragm which couples that motor's movement to motion of air, that is, sound. An audio signal, typically from a microphone, recording, or radio broadcast, is amplified electronically to a power level capable of driving that motor in order to reproduce the sound corresponding to the original unamplified electronic signal. This is thus the opposite function to the microphone; indeed the ''dynamic speaker'' driver, by far the most common type, is a linear motor in the same basic configuration as the dynamic microphone which uses suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conference Room
A conference hall, conference room, or meeting room is a room provided for singular events such as business conferences and meetings. Room It is commonly found at large hotels and convention centers though many other establishments, including even hospitals, have one. Sometimes other rooms are modified for large conferences such as arenas or concert halls. Aircraft have been fitted out with conference rooms. Conference rooms can be windowless for security purposes. An example of one such room is in the Pentagon, known as the ''Tank''. Typically, the facility provides furniture, overhead projectors, stage lighting, and a sound system. Smoking is normally prohibited in conference halls even when other parts of buildings permit smoking. Sometimes the term 'conference hall' is used synonymously with ' conference center' as, for example, in 'Bandaranaike Memorial International Conference Hall'. Some meeting rooms come equipped with booking management software, depending on the need ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speakerphone
A speakerphone is a telephone with a microphone and loudspeaker provided separately from those in the handset. This device allows multiple persons to participate in a conversation. The loudspeaker broadcasts the voice or voices of those on the other end of the telephone line, while the microphone captures all voices of those using the speakerphone. The term speakerphone is also sometimes used for ''loudspeaker'', as in "put it on speakerphone". Many telephones have an integrated speakerphone function which can be activated by pushing a single button. This button transfers the sound input and output from the handset to the ambient microphone and loudspeaker. Devices designed specifically for speakerphone use often have multiple microphone inputs arranged radially around the device to maximize sound input, such as may occur around a conference table. The most sophisticated units allow the connection of additional ''satellite'' microphones that can be placed some distance from the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EE Times
''EE Times'' (''Electronic Engineering Times'') is an electronics industry magazine published in the United States since 1972. EE Times is currently owned by AspenCore, a division of Arrow Electronics since August 2016. Since its acquisition by AspenCore, EE Times has seen major editorial and publishing technology investment and a renewed emphasis on investigative coverage. New features include The Dispatch, which profiles frontline engineers and unpacks the real-life design problems and their solutions in technical yet conversational reporting. Ownership and status ''EE Times'' was launched in 1972 by Gerard G. Leeds of CMP Publications Inc. In 1999, the Leeds family sold CMP to United Business Media for $900 million. After 2000, ''EE Times'' moved more into web publishing. The shift in advertising from print to online began to accelerate in 2007 and the periodical shed staff to adjust to the downturn in revenue. In July 2013, the digital edition migrated to UBM TechWeb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cisco Systems
Cisco Systems, Inc., commonly known as Cisco, is an American-based multinational digital communications technology conglomerate corporation headquartered in San Jose, California. Cisco develops, manufactures, and sells networking hardware, software, telecommunications equipment and other high-technology services and products. Cisco specializes in specific tech markets, such as the Internet of Things (IoT), domain security, videoconferencing, and energy management with leading products including Webex, OpenDNS, Jabber, Duo Security, and Jasper. Cisco is one of the largest technology companies in the world ranking 74 on the Fortune 100 with over $51 billion in revenue and nearly 80,000 employees. Cisco Systems was founded in December 1984 by Leonard Bosack and Sandy Lerner, two Stanford University computer scientists who had been instrumental in connecting computers at Stanford. They pioneered the concept of a local area network (LAN) being used to connect distant c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Feedback
Audio feedback (also known as acoustic feedback, simply as feedback) is a positive feedback situation which may occur when an acoustic path exists between an audio input (for example, a microphone or guitar pickup) and an audio output (for example, a loudspeaker). In this example, a signal received by the microphone is amplified and passed out of the loudspeaker. The sound from the loudspeaker can then be received by the microphone again, amplified further, and then passed out through the loudspeaker again. The frequency of the resulting howl is determined by resonance frequencies in the microphone, amplifier, and loudspeaker, the acoustics of the room, the directional pick-up and emission patterns of the microphone and loudspeaker, and the distance between them. The principles of audio feedback were first discovered by Danish scientist Søren Absalon Larsen, hence it is also known as the Larsen effect. Feedback is almost always considered undesirable when it occurs with a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibels
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 10 (approximately ). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is " V" (e.g., "20 dBV"). Two principal types of scaling of the decibel are in common use. When expressing a power ratio, it is defined as ten times the logarithm in base 10. That is, a change in ''power'' by a factor of 10 corresponds to a 10 dB change in level. When expressing root-power quantities, a change in ''am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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