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Franssen Effect
The Franssen effect is an auditory illusion where the listener incorrectly localizes a sound. It was found in 1960 by Nico Valentinus Franssen (1926–1979), a Dutch physicist and inventor. There are two classical experiments, which are related to the Franssen effect, called Franssen effect F1 and Franssen effect F2. Franssen effect F1 There are two loudspeakers to the left and right of the listener. Each is about 1 meter in distance from the listener, at approximately 45° angles. The left speaker suddenly begins to produce a sharp pure tone. The two speakers are complementary to each other: i.e., as one increases, the other decreases. The left one is decreased exponentially, and the right speaker becomes the main source of the sound. The listener mistakenly perceives the sound as only coming from the left speaker, although the right speaker has been on most of the time. Franssen effect F2 Experiment Inside a room (auditorium) there are two loudspeakers at different position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Illusion
Auditory illusions are false perceptions of a real sound or outside stimulus. These false perceptions are the equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or sounds that should not be possible given the circumstance on how they were created. Humans are fairly susceptible to illusions, despite an innate ability to process complex stimuli. Confirmation bias is believed to be largely responsible for the inaccurate judgments that people make when evaluating information, given that humans typically interpret and recall information that appeals to their own biases. Amongst these misinterpretations, known as illusions, falls the category of auditory illusions. The brain uses multiple senses simultaneously to process information, spatial information is processed with greater detail and accuracy in vision than in hearing. Auditory illusions highlight areas where the human ear and brain, as organic survival tools, differentiate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in W· m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is the sound pressure, * v is the particle velocity. Acoust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory Illusions
Auditory illusions are false perceptions of a real sound or outside stimulus. These false perceptions are the equivalent of an optical illusion: the listener hears either sounds which are not present in the stimulus, or sounds that should not be possible given the circumstance on how they were created. Humans are fairly susceptible to illusions, despite an innate ability to process complex stimuli. Confirmation bias is believed to be largely responsible for the inaccurate judgments that people make when evaluating information, given that humans typically interpret and recall information that appeals to their own biases. Amongst these misinterpretations, known as illusions, falls the category of auditory illusions. The brain uses multiple senses simultaneously to process information, spatial information is processed with greater detail and accuracy in vision than in hearing. Auditory illusions highlight areas where the human ear and brain, as organic survival tools, differentiate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precedence Effect
The precedence effect or law of the first wavefront is a binaural psychoacoustical effect. When a sound is followed by another sound separated by a sufficiently short time delay (below the listener's echo threshold), listeners perceive a single auditory event; its perceived spatial location is dominated by the location of the first-arriving sound (the first wave front). The lagging sound also affects the perceived location. However, its effect is suppressed by the first-arriving sound. The Haas effect was described in 1949 by Helmut Haas in his Ph.D. thesis. It is often equated with the underlying precedence effect. History Joseph Henry published "On The Limit of Perceptibility of a Direct and Reflected Sound" in 1851. The "law of the first wavefront" was described and named in 1948 by Lothar Cremer. The "precedence effect" was described and named in 1949 by Wallach et al. They showed that when two identical sounds are presented in close succession they will be heard as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binaural Fusion
Binaural fusion or binaural integration is a cognitive process that involves the combination of different auditory information presented binaurally, or to each ear. In humans, this process is essential in understanding speech as one ear may pick up more information about the speech stimuli than the other. The process of binaural fusion is important for computing the location of sound sources in the horizontal plane (sound localization), and it is important for sound segregation. Sound segregation refers the ability to identify acoustic components from one or more sound sources. The binaural auditory system is highly dynamic and capable of rapidly adjusting tuning properties depending on the context in which sounds are heard. Each eardrum moves one-dimensionally; the auditory brain analyzes and compares movements of both eardrums to extract physical cues and synthesize auditory objects. When stimulation from a sound reaches the ear, the eardrum deflects in a mechanical fashion, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two different media so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves. The ''law of reflection'' says that for specular reflection (for example at a mirror) the angle at which the wave is incident on the surface equals the angle at which it is reflected. In acoustics, reflection causes echoes and is used in sonar. In geology, it is important in the study of seismic waves. Reflection is observed with surface waves in bodies of water. Reflection is observed with many types of electromagnetic wave, besides visible light. Reflection of VHF and higher frequencies is important for radio transmission and for radar. Even hard X-rays and gamma rays can be reflected at shallow angles with special "grazing" mirrors. Reflection of light Reflection of light is either '' specular'' (mirror-like) or '' diffuse'' (retai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millisecond
A millisecond (from '' milli-'' and second; symbol: ms) is a unit of time in the International System of Units (SI) equal to one thousandth (0.001 or 10−3 or 1/1000) of a second and to 1000 microseconds. A unit of 10 milliseconds may be called a centisecond, and one of 100 milliseconds a decisecond, but these names are rarely used. To help compare orders of magnitude of different times, this page lists times between 10−3 seconds and 100 seconds (1 millisecond and one second). ''See also'' times of other orders of magnitude. Examples The Apollo Guidance Computer used metric units internally, with centiseconds used for time calculation and measurement. *1 millisecond (1 ms) – cycle time for frequency 1 kHz; duration of light for typical photo flash strobe; time taken for sound wave to travel about 34 cm; repetition interval of GPS C/A PN code *1 millisecond - time taken for light to travel 204.19 km in a single mode fiber optic cable for a wav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harmonic Series (music)
A harmonic series (also overtone series) is the sequence of harmonics, musical tones, or pure tones whose frequency is an integer multiple of a ''fundamental frequency''. Pitched musical instruments are often based on an acoustic resonator such as a string or a column of air, which oscillates at numerous modes simultaneously. At the frequencies of each vibrating mode, waves travel in both directions along the string or air column, reinforcing and canceling each other to form standing waves. Interaction with the surrounding air causes audible sound waves, which travel away from the instrument. Because of the typical spacing of the resonances, these frequencies are mostly limited to integer multiples, or harmonics, of the lowest frequency, and such multiples form the harmonic series. The musical pitch of a note is usually perceived as the lowest partial present (the fundamental frequency), which may be the one created by vibration over the full length of the string or ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reverberation
Reverberation (also known as reverb), in acoustics, is a persistence of sound, after a sound is produced. Reverberation is created when a sound or signal is reflected causing numerous reflections to build up and then decay as the sound is absorbed by the surfaces of objects in the space – which could include furniture, people, and air. This is most noticeable when the sound source stops but the reflections continue, their amplitude decreasing, until zero is reached. Reverberation is frequency dependent: the length of the decay, or reverberation time, receives special consideration in the architectural design of spaces which need to have specific reverberation times to achieve optimum performance for their intended activity. In comparison to a distinct echo, that is detectable at a minimum of 50 to 100 ms after the previous sound, reverberation is the occurrence of reflections that arrive in a sequence of less than approximately 50 ms. As time passes, the amplitude of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experiment
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated. Experiments vary greatly in goal and scale but always rely on repeatable procedure and logical analysis of the results. There also exist natural experimental studies. A child may carry out basic experiments to understand how things fall to the ground, while teams of scientists may take years of systematic investigation to advance their understanding of a phenomenon. Experiments and other types of hands-on activities are very important to student learning in the science classroom. Experiments can raise test scores and help a student become more engaged and interested in the material they are learning, especially when used over time. Experiments can vary from personal and informal natural comparisons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auditory System
The auditory system is the sensory system for the sense of hearing. It includes both the sensory organs (the ears) and the auditory parts of the sensory system. System overview The outer ear funnels sound vibrations to the eardrum, increasing the sound pressure in the middle frequency range. The middle-ear ossicles further amplify the vibration pressure roughly 20 times. The base of the stapes couples vibrations into the cochlea via the oval window, which vibrates the perilymph liquid (present throughout the inner ear) and causes the round window to bulb out as the oval window bulges in. Vestibular and tympanic ducts are filled with perilymph, and the smaller cochlear duct between them is filled with endolymph, a fluid with a very different ion concentration and voltage. Vestibular duct perilymph vibrations bend organ of Corti outer cells (4 lines) causing prestin to be released in cell tips. This causes the cells to be chemically elongated and shrunk ( somatic motor), and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from families and kinship networks to political states. Social interactions between humans have established a wide variety of values, social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generally refers to ''Homo sapiens'', the only Extant taxon, extant member. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
