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Comfort Noise
Comfort noise (or comfort tone) is synthetic background noise used in radio and wireless communications to fill the artificial silence in a transmission resulting from voice activity detection or from the audio clarity of modern digital lines. Some modern telephone systems (such as wireless and VoIP) use voice activity detection (VAD), a form of squelching where low volume levels are ignored by the transmitting device. In digital audio transmissions, this saves bandwidth of the communications channel by transmitting nothing when the source volume is under a certain threshold, leaving only louder sounds (such as the speaker's voice) to be sent. However, improvements in background noise reduction technologies can occasionally result in the complete removal of all noise. Although maximizing call quality is of primary importance, exhaustive removal of noise may not properly simulate the typical behavior of terminals on the PSTN system. The result of receiving total silence, es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Background Noise
Background noise or ambient noise is any sound other than the sound being monitored (primary sound). Background noise is a form of noise pollution or interference. Background noise is an important concept in setting noise levels. Background noises include environmental noises such as water waves, traffic noise, alarms, extraneous speech, bioacoustic noise from animals, and electrical noise from devices such as refrigerators, air conditioning, power supplies, and motors. The prevention or reduction of background noise is important in the field of active noise control. It is an important consideration with the use of ultrasound (e.g. for medical diagnosis or imaging), sonar, and sound reproduction. Other uses In astronomy, background noise or cosmic background radiation is electromagnetic radiation from the sky with no discernible source. In information architecture, irrelevant, duplicate or incorrect information may be called background noise. In physics and telecommunic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sidetone
Sidetone is audible feedback to someone speaking or otherwise producing sound as an indication of active transmission. Sidetone is introduced by some communications circuits and anti-sidetone circuitry is used to control its level. Sidetone is expected behavior for telephone systems. Absence of sidetone can cause users to believe the call has been dropped or cause them to speak loudly. Too much sidetone can cause users to speak softly. Telephony In telephony, sidetone is the effect of sound picked up by the telephone's transmitter (mouthpiece) and instantly introduced at a low electronic signal level into the receiver (earpiece) of the same handset, a form of electrical feedback through the telephone hybrid.AT&T, ''Bell System Practices'', Section C30.001 Issue 1 (March 16, 1932) ''Common Battery Anti-Sidetone Stations'' Sidetone in early 19th century telephones was strong due to the type of circuit used in instruments. Anti-sidetone circuitry in the telephone hybrid brought sideto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arises when the brain receives and perceives a sound. Acoustic noise is any sound in the acoustic domain, either deliberate (e.g., music or speech) or unintended. In contrast, noise in electronics may not be audible to the human ear and may require instruments for detection. In audio engineering, noise can refer to the unwanted residual electronic noise signal that gives rise to acoustic noise heard as a hiss. This signal noise is commonly measured using A-weighting or ITU-R 468 weighting. In experimental sciences, noise can refer to any random fluctuations of data that hinders perception of a signal. Measurement Sound is measured based on the amplitude and frequency of a sound wave. Amplitude measures how forceful the wave is. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dead Air
Dead air is an unintended period of silence that interrupts a broadcast during which no audio or video program material is transmitted. Radio and television Dead air occurs in radio broadcasting when no audio program is transmitted for an extended period of time, usually more than a few seconds. In television broadcasting, the term denotes the absence of both audio and video program material. However, a carrier wave is still transmitting. In radio, the result is silence, and in television, the result is a silent black or gray screen. Television directors may use the command "fade to black" or "to black" to indicate a momentary transition to a completely black image. However, the term "dead air" is most often used in cases where program material comes to an unexpected halt, either through operator error or technical malfunction. Among professional broadcasters, dead air is considered one of the worst things that can occur. Moreover, dead air may impact advertising revenue if ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Masking
Sound masking is the inclusion of generated sound (commonly, though inaccurately, referred to as "white noise" or "pink noise") into an environment to mask unwanted sound. It relies on auditory masking. Sound masking is not a form of active noise control (noise cancellation technique); however, it can reduce or eliminate the perception of sound. Sound masking is applied to an entire area to improve acoustical satisfaction, thus improving the acoustical privacy of the space. This can help an individual focus and thereby enhance productivity. Architectural acoustics Sound masking means controlling background sounds in a developed environment. It is significant and prioritizes modifying the background sound (in contrast to background noise); however, there is substantial evidence produced and published by Banneker (BBN) and Kavanaugh (et al., 1962 ''Speech Privacy in Buildings'') indicating that acoustical satisfaction within a space cannot be guaranteed without consideration of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autonomous Sensory Meridian Response
Autonomous sensory meridian response (ASMR) is a tingling sensation that usually begins on the scalp and moves down the back of the neck and upper spine. A pleasant form of paresthesia, it has been compared with auditory-tactile synesthesia and may overlap with frisson. ASMR signifies the subjective experience of "low-grade euphoria" characterized by "a combination of positive feelings and a distinct static-like tingling sensation on the skin." It is most commonly triggered by specific auditory or visual stimuli, and less commonly by intentional attention control. A genre of videos intended to induce ASMR has emerged, over 25 million of which had been published on YouTube by 2022 and a dedicated category of live ASMR streams on Twitch. Etymology Although many colloquial and formal terms used and proposed between 2007 and 2010 included reference to orgasm, a significant majority objected to its use among those active in online discussions. Many differentiate between the eupho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Presence (sound Recording)
In filmmaking and television production, presence, also known as room tone, or simply room sound, is the "silence" recorded at a location or space when no dialogue is spoken. Presence is similar to ambience, but is distinguished by a lack of explicit background noise. Every location has a distinct presence created by the position of the microphone in relation to the space boundaries. A microphone placed in two different parts of the same room will record two distinct presences. This is because of the unique spatial relationship between the microphone and boundaries such as walls, ceilings, and floors, and other objects in a room. Presence is recorded during the production stage of filmmaking. It is used to help create the film sound track, where presence may be intercut with dialogue to smooth out any sound edit points. The sound track "going dead" would be perceived by the audience not as silence, but as a failure of the sound system. For this reason presence is normally recorde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discontinuous Transmission
Discontinuous transmission (DTX) is a means by which a mobile telephone is temporarily shut off or muted while the phone lacks a voice input. Misconception A common misconception is that DTX improves capacity by freeing up TDMA time slots for use by other conversations. In practice, the unpredictable availability of time slots makes this difficult to implement. However, reducing interference is a significant component in how GSM and other TDMA based mobile phone systems make better use of the available spectrum compared to older analog systems such as Advanced Mobile Phone System (AMPS) and Nordic Mobile Telephone (NMT). While older network types theoretically allocated two 25–30 kHz channels per conversation, in practice some radios would cause interference on neighbouring channels making them unusable, and a single radio may broadcast too strong an oval signal pattern to let nearby cells reuse the same channel. GSM combines short packet sizes, frequency hopping, redund ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ambient Noise
Background noise or ambient noise is any sound other than the sound being monitored (primary sound). Background noise is a form of noise pollution or interference. Background noise is an important concept in setting noise levels. Background noises include environmental noises such as water waves, traffic noise, alarms, extraneous speech, bioacoustic noise from animals, and electrical noise from devices such as refrigerators, air conditioning, power supplies, and motors. The prevention or reduction of background noise is important in the field of active noise control. It is an important consideration with the use of ultrasound (e.g. for medical diagnosis or imaging), sonar, and sound reproduction. Other uses In astronomy, background noise or cosmic background radiation is electromagnetic radiation from the sky with no discernible source. In information architecture, irrelevant, duplicate or incorrect information may be called background noise. In physics and telecommunic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remembrance Sunday
Remembrance Sunday is held in the United Kingdom as a day to commemorate the contribution of British and Commonwealth military and civilian servicemen and women in the two World Wars and later conflicts. It is held on the second Sunday in November (the Sunday nearest to 11 November, Armistice Day, the anniversary of the end of hostilities in World War I in 1918). Remembrance Sunday, within the Church of England, falls in the liturgical period of Allsaintstide. It is marked by ceremonies at local war memorials in most cities, towns and villages, attended by civic dignitaries, ex-servicemen and -women (many are members of the Royal British Legion and other veterans' organisations), members of local armed forces regular and reserve units (Royal Navy and Royal Naval Reserve, Royal Marines and Royal Marines Reserve, Army and Territorial Army, Royal Air Force and Royal Auxiliary Air Force), military cadet forces (Sea Cadet Corps, Army Cadet Force and Air Training Corps as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Network
There are two types of radio network currently in use around the world: the one-to-many (simplex communication) broadcast network commonly used for public information and mass media, mass-media entertainment, and the two-way radio (Duplex (telecommunications), duplex communication) type used more commonly for public safety and public services such as police, fire, taxicabs, and delivery services. Cell phones are able to send and receive simultaneously by using two different frequencies at the same time. Many of the same components and much of the same basic technology applies to all three. The two-way type of radio network shares many of the same technologies and components as the broadcast-type radio network but is generally set up with fixed broadcast points (transmitters) with co-located receivers and mobile receivers/transmitters or transceivers. In this way both the fixed and mobile radio units can communicate with each other over broad geographic regions ranging in size from s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
