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Perceptual Evaluation Of Audio Quality
Perceptual Evaluation of Audio Quality (PEAQ) is a standardized algorithm for objectively measuring perceived audio quality, developed in 1994-1998 by a joint venture of experts within Task Group 6Q of the International Telecommunication Union's Radiocommunication Sector (ITU-R). It was originally released as ITU-R Recommendation BS.1387 in 1998 and last updated in 2001. It utilizes software to simulate perceptual properties of the auditory system, human ear and then integrates multiple model output variables into a single metric. PEAQ characterizes the perceived audio quality as subjects would do in a listening test according to ITU-R BS.1116. PEAQ results principally model mean opinion scores that cover a scale from 1 (bad) to 5 (excellent). Motivation The need to conserve bandwidth has led to developments in the compression of the audio data to be transmitted. Various codec, encoding methods remove both redundancy and perceptual irrelevancy in the audio signal so that the bit ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Quality
Sound quality is typically an assessment of the accuracy, fidelity, or intelligibility of audio output from an electronic device. Quality can be measured objectively, such as when tools are used to gauge the accuracy with which the device reproduces an original sound; or it can be measured subjectively, such as when human listeners respond to the sound or gauge its ''perceived'' similarity to another sound. The sound quality of a reproduction or recording depends on a number of factors, including the equipment used to make it, processing and mastering done to the recording, the equipment used to reproduce it, as well as the listening environment used to reproduce it. In some cases, processing such as equalization, dynamic range compression or stereo processing may be applied to a recording to create audio that is significantly different from the original but may be perceived as more agreeable to a listener. In other cases, the goal may be to reproduce audio as closely as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subjective Difference Grade
Subjective may refer to: * Subjectivity, a subject's personal perspective, feelings, beliefs, desires or discovery, as opposed to those made from an independent, objective, point of view ** Subjective experience, the subjective quality of conscious experience * Subjectivism, a philosophical tenet that accords primacy to subjective experience as fundamental of all measure and law * Subjective case, grammatical case for a noun * Subject (philosophy), who has subjective experiences or a relationship with another entity * Subjective theory of value, an economic theory of value * A school of bayesian probability stating that the state of knowledge corresponds to personal belief * ''Subjectivity'' (journal), an academic journal See also * Subjectivist fallacy * Subjunctive * Objective (other) Objective may refer to: * Objective (optics), an element in a camera or microscope * '' The Objective'', a 2008 science fiction horror film * Objective pronoun, a personal pron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Audio
Digital audio is a representation of sound recorded in, or converted into, digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical samples in a continuous sequence. For example, in CD audio, samples are taken 44,100 times per second, each with 16-bit sample depth. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s and 1980s, it gradually replaced analog audio technology in many areas of audio engineering, record production and telecommunications in the 1990s and 2000s In a digital audio system, an analog electrical signal representing the sound is converted with an analog-to-digital converter (ADC) into a digital signal, typically using pulse-code modulation (PCM). This digital signal can then be recorded, edited, modified, and copied using computer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Codecs
An audio codec is a device or computer program capable of encoding or decoding a digital data stream (a codec) that encodes or decodes audio. In software, an audio codec is a computer program implementing an algorithm that compresses and decompresses digital audio data according to a given audio file or streaming media audio coding format. The objective of the algorithm is to represent the high-fidelity audio signal with minimum number of bits while retaining quality. This can effectively reduce the storage space and the bandwidth required for transmission of the stored audio file. Most software codecs are implemented as libraries which interface to one or more multimedia players. Most modern audio compression algorithms are based on modified discrete cosine transform (MDCT) coding and linear predictive coding (LPC). In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back into analog. In other words, it contains bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Quality
Sound quality is typically an assessment of the accuracy, fidelity, or intelligibility of audio output from an electronic device. Quality can be measured objectively, such as when tools are used to gauge the accuracy with which the device reproduces an original sound; or it can be measured subjectively, such as when human listeners respond to the sound or gauge its ''perceived'' similarity to another sound. The sound quality of a reproduction or recording depends on a number of factors, including the equipment used to make it, processing and mastering done to the recording, the equipment used to reproduce it, as well as the listening environment used to reproduce it. In some cases, processing such as equalization, dynamic range compression or stereo processing may be applied to a recording to create audio that is significantly different from the original but may be perceived as more agreeable to a listener. In other cases, the goal may be to reproduce audio as closely as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perceptual Evaluation Of Video Quality
Perceptual Evaluation of Video Quality (PEVQ) is an end-to-end (E2E) measurement algorithm to score the picture quality of a video presentation by means of a 5-point mean opinion score (MOS). It is, therefore, a video quality model. PEVQ was benchmarked by the Video Quality Experts Group (VQEG) in the course of the Multimedia Test Phase 2007–2008. Based on the performance results, in which the accuracy of PEVQ was tested against ratings obtained by human viewers, PEVQ became part of the new International Standard. (2008) Application The measurement algorithm can be applied to analyze visible artifacts caused by a digital video encoding/decoding (or transcoding) process, radio- or IP-based transmission networks and end-user devices. Application scenarios address |
Perceptual Evaluation Of Speech Quality
Perception () is the organization, identification, and interpretation of sensory information in order to represent and understand the presented information or environment. All perception involves signals that go through the nervous system, which in turn result from physical or chemical stimulation of the sensory system.Goldstein (2009) pp. 5–7 Vision involves light striking the retina of the eye; smell is mediated by odor molecules; and hearing involves pressure waves. Perception is not only the passive receipt of these signals, but it is also shaped by the recipient's learning, memory, expectation, and attention. Gregory, Richard. "Perception" in Gregory, Zangwill (1987) pp. 598–601. Sensory input is a process that transforms this low-level information to higher-level information (e.g., extracts shapes for object recognition). The process that follows connects a person's concepts and expectations (or knowledge), restorative and selective mechanisms (such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective Difference Grade
In digital audio, the objective difference grade (ODG) is calculated by perceptual evaluation of the audio quality algorithm specified in ITU BS.1387-1.(PEAQ) It corresponds to the subjective difference grade Subjective may refer to: * Subjectivity, a subject's personal perspective, feelings, beliefs, desires or discovery, as opposed to those made from an independent, objective, point of view ** Subjective experience, the subjective quality of consc ... used in human-based audio tests.''Introduction to Digital Audio Coding and Standards'', by Marina Bosi and Richard E. Goldberg, Kluwer Academic Publishers (2002) . The ODG ranges from 0 to −4 and is defined as follows: References Further reading * * Digital audio {{radio-comm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hearing-Aid Speech Quality Index
Hearing-Aid Speech Quality Index (HASQI) is a measure of audio quality originally designed for the evaluation of speech quality for those with a hearing aid,. It has also been shown to be able to gauge audio quality for non-speech sounds and for listeners without a hearing loss. Background While the perception of audio quality can be gauged through perceptual measurements, the testing is time-consuming to undertake. Consequently, a number of metrics have been developed to allow audio quality to be evaluated without the need for human listening. Standardized examples from telephony include PESQ, POLQA, PEVQ and PEAQ. HASQI was originally developed by Kates and Arehart to evaluate how the distortions introduced by hearing aids degrade quality. They also produced a new version in 2014. Kressner et al. tested a speech corpus different from the dataset used to develop HASQI and showed that the index generalizes well for listeners without a hearing loss with a performance comparable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Masking
In audio signal processing, auditory masking occurs when the perception of one sound is affected by the presence of another sound.Gelfand, S.A. (2004) ''Hearing – An Introduction to Psychological and Physiological Acoustics'' 4th Ed. New York, Marcel Dekker Auditory masking in the frequency domain is known as simultaneous masking, frequency masking or spectral masking. Auditory masking in the time domain is known as temporal masking or non-simultaneous masking. Masked threshold The ''unmasked threshold'' is the quietest level of the signal which can be perceived without a masking signal present. The ''masked threshold'' is the quietest level of the signal perceived when combined with a specific masking noise. The amount of masking is the difference between the masked and unmasked thresholds. Gelfand provides a basic example.Gelfand, S.A. (2004) ''Hearing – An Introduction to Psychological and Physiological Acoustics'' 4th Ed. New York, Marcel Dekker Let us say that for a g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Compression (data)
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound *Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum *Digital audio, representation of sound in a form processed and/or stored by computers or digital electronics *Audio, audible content (media) in audio production and publishing *Semantic audio, extraction of symbols or meaning from audio * Stereophonic audio, method of sound reproduction that creates an illusion of multi-directional audible perspective * Audio equipment Entertainment *AUDIO (group), an American R&B band of 5 brothers formerly known as TNT Boyz and as B5 * ''Audio'' (album), an album by the Blue Man Group * ''Audio'' (magazine), a magazine published from 1947 to 2000 *Audio (musician), British drum and bass artist * "Audio" (song), a song by LSD Computing *, an HTML element, see HTML5 audio See also *Acoustic (other) *Audible (other) *Aud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reasonable And Non-discriminatory Licensing
Reasonable and non-discriminatory (RAND) terms, also known as fair, reasonable, and non-discriminatory (FRAND) terms, denote a voluntary licensing commitment that standards organizations often request from the owner of an intellectual property right (usually a patent) that is, or may become, essential to practice a technical standard. Put differently, a F/RAND commitment is a voluntary agreement between the standard-setting organization and the holder of standard-essential patents. U.S. courts, as well as courts in other jurisdictions, have found that, in appropriate circumstances, the implementer of a standard—that is, a firm or entity that uses a standard to render a service or manufacture a product—is an intended third-party beneficiary of the FRAND agreement, and, as such, is entitled to certain rights conferred by that agreement. A standard-setting organization is an industry group that sets common standards for its particular industry to ensure compatibility and intero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
