Term
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Definition
| repetitive motion at equal time intervals |
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Term
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Definition
| periodic motion about a point of equilibrium |
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Term
| Simple Harmonic Oscillator |
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Definition
| any object with periodic vibration or motion |
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Term
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Definition
| time to complete one full cycle of a wave |
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Term
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Definition
| number of complete wave cycles per second (Hertz) |
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Term
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Definition
| distance moved from zero point or equilibrium |
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Term
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Definition
| amount of displacement from zero point (level or voltage) |
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Term
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Definition
| length of one complete cycle of a wave |
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Term
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Definition
| resting state; zero state |
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Term
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Definition
| magnitude and direction of displacement |
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Term
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Definition
| decrease in amplitude from internal and external resistive forces (linear restorative force) |
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Term
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Definition
| property of mass or a system to return to its original state after being stretched or compressed; restoring force |
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Term
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Definition
| property of mass to stay in motion or at rest until acted upon by external forces (Newtonʼs First Law of Motion) |
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Term
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Definition
| fundamental form of all complex waveforms; pure tone with all energy concentrated at one frequency (only one harmonic, the fundamental) |
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Term
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Definition
| Period ! Frequency ! Wavelength ! Amplitude ! Velocity |
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Term
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Definition
| how quickly energy can be transferred through the molecular content of a medium (1130 ft./sec. or 344 m/sec at standard atmospheric pressure and 20o C) {Sound travels approximately 1.13 feet per millisecond} |
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Term
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Definition
| pressure wave movement through a medium from an energetic force or disturbance |
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Term
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Definition
| mechanical wave motion consisting of compressions and rarefactions |
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Term
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Definition
| movement of particles in a medium from a state of equilibrium caused by pressure wave energy |
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Term
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Definition
| frequencies that have a mathematical relationship to a fundamental tone (naturally resonating frequencies) |
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Term
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Definition
| frequencies that are whole number multiples above a fundamental frequency (musically pleasing) |
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Term
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Definition
| doubling or halving a frequency |
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Term
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Definition
| any harmonic without regard to a fundamental or mathematic formula |
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Term
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Definition
| 12 tone chromatic harmonic series used in Western music |
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Term
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Definition
| allows the analysis of frequency, harmonic content, amplitude and phase of complex waveforms; transfer of a form or function into its fundamental components; transfer from the time domain to the frequency domain |
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Term
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Definition
| quality of sound dependent on harmonic content |
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Term
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Definition
| attack, decay, sustain and release; sound envelope that also determines sound quality |
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Term
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Definition
| random particle displacement without periodic motion |
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Term
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Definition
| measurement of overall frequency response of a source, system or environment |
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Term
| Distortion (Non-Linearity) |
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Definition
| any change to a signal from an input stage to an output stage through an environment, system or device |
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Term
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Definition
| any change in amplitude of harmonic content |
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Term
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Definition
| any amplitude changes greater than maximum level |
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Term
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Definition
| any distortion of a waveform usually resulting in a square wave at the extreme |
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Term
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Definition
| any alteration of the phase relationship of audio signals |
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Term
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Definition
| the ability of one signal to cover another |
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Term
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Definition
| the combining of frequency, amplitude and phase of individual waves traversing the same medium at the same time |
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Term
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Definition
| any physical quantity that has both magnitude and direction (velocity, displacement, acceleration) |
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Term
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Definition
| any physical quantity that possesses magnitude only (speed, distance, temperature) |
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Term
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Definition
| distortion that occurs when multiple waves meet or overlap within the same medium |
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Term
| Constructive Interference |
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Definition
| positive reinforcement when waves interact (amplitude increase) |
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Term
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Definition
| negative reinforcement when waves interact (phase cancellation) |
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Term
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Definition
| periodic changes in amplitude when two signals are close in frequency |
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Term
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Definition
| wave pattern representing the effect of interference of waves in a medium; not a “true” wave |
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Term
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Definition
| area of minimum displacement in a standing wave |
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Term
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Definition
| area of maximum displacement in a standing wave |
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Term
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Definition
| natural vibrational frequency of an object or environment; frequency that occurs at an antinode |
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Term
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Definition
| waves from a direct sound that encounter a boundary |
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Term
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Definition
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Term
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Definition
| angle of reflection; equal to the angle of the incident wave |
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Term
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Definition
| any area containing sound waves |
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Term
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Definition
| sound field devoid of boundaries |
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Term
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Definition
| immediate area surrounding direct sound |
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Term
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Definition
| area where direct sound and reflections interact |
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Term
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Definition
| area of a sound field where inverse square law still applies |
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Term
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Definition
| area of sound field where reflections tend to have a greater amplitude than the direct sound; loss of intelligibility |
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Term
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Definition
| for every doubling of distance from a source there is a decrease of -6.02 dB |
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Term
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Definition
| change in speed of sound when encountering mediums of differing densities |
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Term
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Definition
| change in direction of sound when encountering boundaries |
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Term
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Definition
| perceived localization of sound when direct sound and short reflections are combined in the ear (delay time of reflections within 1 mSec-30 mSec); also known as the Precedence effect |
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Term
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Definition
| reinforcement and cancellation of interfering waves when arrival time of reflections are very short (1 mSec to 30 mSec); series of harmonically related peaks and nulls across full audio spectrum |
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Term
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Definition
| collects and funnels sound to the auditory canal; imprints localization " data |
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Term
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Definition
| small opening of auditory canal |
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Term
Outer Ear:
Auditory Canal (Ear Canal) |
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Definition
| closed duct (or pipe) terminated by the tympanic membrane; generates resonant frequencies |
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Term
Outer Ear:
Tympanic Membrane (Ear Drum) |
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Definition
| small, semi-transparent, oval-shaped membrane that responds to and transmits sound pressure |
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Term
Middle Ear:
(Tympanic Cavity) |
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Definition
| air-filled cavity that contains the smallest bones and muscles of the human body |
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Term
Middle Ear:
Tympanic Membrane |
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Definition
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Term
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Definition
| malleus, incus and stapes; the small bone chain of the middle ear |
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Term
Middle Ear:
Malleus (Hammer) |
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Definition
| connected to the ear drum the malleus transmits the vibrational content it receives from the ear drum to the incus through mechanical action |
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Term
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Definition
| once set into motion by the malleus the incus transmits vibrational energy to the stapes |
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Term
Middle Ear:
Stapes (Stirrup) |
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Definition
| the movement of the stapes against the oval window of the inner ear transfers acoustic energy from air to fluid |
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Term
Middle Ear:
Tensor Tympani |
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Definition
| small muscle and tendon attached to the malleus that protects the auditory system from excessive sound energy; restricts movement of ear drum by contracting (form of natural compression) |
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Term
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Definition
| small muscle and tendon attached to the stapes that moves the stapes " away from the oval window when contracted; protection from loud source signals |
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Term
Middle Ear:
Eustachian Tube |
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Definition
| small tube connected to the the throat that maintains equal pressure on both sides of the tympanic membrane; drains middle ear when infections are present |
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Term
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Definition
| small membrane of the cochlea; receives mechanical energy from the stapes and transmits it as pressure waves to the fluid inside the cochlea |
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Term
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Definition
| ”sound analyzing organ”; small, coiled, shell shaped organ that analyzes all sound entering the auditory canal |
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Term
Inner Ear:
Semi-circular Canals |
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Definition
| three fluid-filled canals responsible for our sense of balance and equilibrium on various axes; detect angular motion on three axes |
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Term
Inner Ear:
Basilar Membrane |
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Definition
| membrane separating two fluid-filled tubes along the length of the cochlea; serves as a base for auditory sensory cells; responds to pressure waves in cochlear fluid |
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Term
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Definition
| central organ of the cochlea containing the hair cells |
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Term
Inner Ear:
Tectorial Membrane |
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Definition
| gelatinous membrane in which the stereocilia are embedded; movement of basilar membrane causes shearing of stereocilia under the tectorial membrane |
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Term
Inner Ear:
Inner Hair Cells |
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Definition
| receives mechanical vibrations from outer hair cells, converts mechanical energy into neural impulses |
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Term
Inner Ear:
Outer Hair Cells |
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Definition
| referred to as the cochlear amplifier, provides sharper tuning of audio signals; increases auditory sensitivity; also capable of not only receiving signals but can transmit signals from within the brain |
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Term
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Definition
| bundles tiny sense organelles that sit atop hair cells; respond to specific frequencies |
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Term
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Definition
| high K concentration, similar to intracellular fluids, low Na content; " supposedly causes metabolic actions within the hair cells |
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Term
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Definition
| high Na concentration, similar to spinal fluid, low K content; supposedly causes metabolic actions within the hair cells |
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Term
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Definition
| small membrane of the cochlea that responds to the pressure changes transmitted through the cochlear fluid from the oval window (compression and rarefaction); acts as a pressure valve |
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Term
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Definition
| level of discernible difference in human hearing; 20 μPa (20 x 10-6 referenced at 0 dB |
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Term
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Definition
| level of noticeable discomfort or pain 200,000,000 x 10-6 Pascals); referenced as 120 dB |
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Term
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Definition
| sonic range of human auditory system (20 Hz-20 KHz) |
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Term
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Definition
| displays the changes in sensitivity of human hearing to frequencies across the audible range |
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Term
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Definition
| audible ranges of speech, music and overall sound Critical Bands-areas along the basilar membrane that vibrate in response to certain frequencies; frequency ranges around a center frequency that allow us to discern individual frequencies in complex waveforms |
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Term
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Definition
| the ability of the ear to detect a missing fundamental in a mathematical related harmonic series |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| 1130/f (feet/second) or 334/f (meters/second) |
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Term
Equation:
Inverse Square Law |
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Definition
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Term
Equation:
Comb Filter (first null) |
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Definition
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Term
Equation:
Comb Filter (first peak) |
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Definition
| f=1/T (also equals distance between peaks) |
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Term
Equation:
Chromatic Half Step |
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Definition
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