Term
___ is a transducer that transduces acoustical energy (sound
pressure) into electrical energy (voltage) for the purpose of transmitting or recording |
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Definition
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Term
Microphone:
-Acts as a ___ sensor calibrated to the measurement of small variations in air pressure
-Most commonly, vibration of a thin membrane (diaphragm) is
used to produce a ___ proportional to the ___ of the vibration |
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Definition
| pressure; voltage; magnitude |
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Term
Microphone: Transduction is accomplished by...
-___ generation (dynamic microphones)
–___ charge (condenser microphones)
–___ generation (piezoelectric microphones) |
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Definition
| Electromagnetic; Capacitance; Piezoelectric |
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Term
Microphone:
-the amount of current depends on how the distance of the diaphragm changes in relation to the ___ |
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Definition
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Term
Condenser Microphone:
-Contains a diaphragm mounted above a back plate to form a ___
-Internal charge held ___; voltage varies as pressure actuates the ___. Requires an ___ voltage supply or a charged diaphragm
-Acoustical performance determined by ___ dimensions
-Small signal – requires a ___ |
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Definition
| capacitor; constant; diaphragm; external; physical; preamplifier[image] |
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Term
| Storage of electrical charge |
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Definition
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Term
| Most common type of condensor microphone used in audiology and hearing science applications (including modern hearing aids) |
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Definition
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Term
Electret Microphone:
-Diaphragm permanently ___ like a magnet (electrostatic magnet), avoiding the necessity of a biasing DC voltage
-It has a wide ___ range in terms of frequency and a flat frequency response, that is, ___ energy across the wide dynamic range
-This mic is ___ (having its own charge) and can last for more than ___ years
-not ___; has a charge |
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Definition
| polarized; dynamic; equal; self-biased; 100; neutral |
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Term
| An electronic device that amplifies a signal to prepare it to be amplified or processed by an amplifier; amplifies signal before any processing occurs |
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Definition
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Term
| Generally, the function of the pre- amp is to amplify a microphone’s tiny signal to “___-___” (voltage necessary to drive the amplifier) |
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Definition
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Term
Condenser microphone advantages:
-Can be manufactured to very ___ size
– Excellent ___ response (better than dynamic mics)
– Excellent ___ quality
– Usually low internal ___ |
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Definition
| small; frequency; sound; noise |
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Term
Condesner microphone disadvantages:
-May require ___ power source
– More ___ in construction than dynamic mics
– Has maximum ___ it can handle
– Affected by ___ and ___
– Cheap or malfunctioning condensers will create internal ___ |
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Definition
| external; complex; SPL; temperature; humidity; noise |
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Term
Dynamic Microphone:
-___ wire coil attached to a robust diaphragm
-Unmovable magnet produces a ___ ___
-Moving diaphragm moves the coil within the magnetic field, inducing a measurable ___. The reverse of the way a ___ works.
-Commonly used for ____ and ___ performances on stage |
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Definition
| Movable; magnetic field; current; speaker; musical; dramatic |
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Term
-Note that the dynamic microphone has the following components: diaphragm, magnet, coil, and wires that carry the electrical signal into an electrical system.
-The diaphragm is attached to the ___. The coil moves in synchrony to the ___ ___ when the diaphragm vibrates in response to an incoming acoustic signal. |
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Definition
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Term
| Dynamic microphones are known for ___ reduction and bass ___-___. These microphones are used for ___ ___ systems, recording, and have a ___ shape to concentrate energy. They are usually ___ in cost. Dynamic microphones can record both ___ and ___ signals. |
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Definition
| noise; roll-off; public address; cone; low; digital; analog |
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Term
| The dynamic microphone is often used in clinical audiology especially for the test-microphone monitor on the ___. ____, rather than conventional, magnets are sometimes used for the dynamic microphone as they are more powerful. Neodymium microphones are ___, with a uniform frequency response and higher ___ output. |
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Definition
| audiometer; Neodymium; smaller; volume |
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Term
Dynamic Microphone advantages:
-Simple and ___ to construct
-Can handle ___ SPLs (hard to overdrive)
-Resistant to ___ change and ___
-Generally more ___ (less delicate) than other microphone types
-Poor low-frequency response reduces noise
-No internal noise |
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Definition
| inexpensive; high; temperature; humidity; robust |
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Term
Dynamic microphone disadvantages:
-___ and ___ than condenser mics
-___ response –takes longer to stop and start moving, reducing sensitivity to ___ sounds
–Poorer ___ quality
–Poorer ___ response |
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Definition
| Larger; heavier; Slower; transient; sound; frequency |
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Term
| The quality and utility of a microphone is dictated by what 8 characteristics? |
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Definition
| sound source, equipment, cost, physical setting, sensitivity, frequency response, directionality, and noise |
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Term
| Amount of electrical output produced by a microphone for a given SPL input |
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Definition
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Term
Sensitivity:
-The relationship between the size of the output ___ and the input ___ ___
-If two microphones are subjected to the same SPL and one puts out a ___ voltage signal, that one is considered to be the more sensitive microphone |
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Definition
| voltage; sound pressure; higher |
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Term
| Is higher sensitivity in a microphone always better? |
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Definition
| No. It is if you are trying to amplify sound in a hearing aid for soft sounds. If there are loud sounds though it could damage the microphone. |
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Term
The pattern of the microphone’s intensity output for inputs at different frequencies (amplitude or voltage as a function of
frequency) |
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Definition
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Term
Frequency Response:
-Often expressed using a ___ (i.e., 20 – 20,000 Hz) and an expression of the ___ in the response (i.e., 100 dB SPL +/- 3 dB at 1000 Hz)
-___ frequency response is a desirable response |
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Definition
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Term
| Equal sensitivity at all angles |
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Definition
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Term
-No microphone is ___
-“excellent for ___ discussions, ___ groups, and so forth” |
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Definition
| omnidirectional; group; vocal |
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Term
Bi-directional:
-Strong output level or sensitivity at __ and __ degrees
-Weak output level or sensitivity at __ and ___ degrees |
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Definition
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Term
| Bidirectional microphones pick up sounds from ___ and ___ while rejecting sound from ___ ___ |
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Definition
| front and back; both sides. |
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Term
| High sensitivity at 0 degrees but reduced as sound moves off of the axis |
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Definition
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Term
| Unidirectional mikes, also called cardiod mics because they are similar in configuration to the ___ ___, pick up sound from one direction (the front), and separate speech and other desired signals from background noise. |
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Definition
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Term
| The unidirectional microphone is good for ___-___ speech audiometry, lectures, and so forth. However, on occasion, the unidirectional microphone exhibits an undesirable proximity effect that boosts ___ frequencies, especially when the speaker’s mouth is near the microphone. This is why we often see TV interviewers moving the mic ___ and ___ to avoid a proximity effect |
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Definition
| live-voice; low; back and forth |
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Term
-The frequency response of a microphone affects its overall ___ (shape of the polar plot)
-___ frequencies travel in a straight line longer before they spread out whereas ___ frequencies spread out from the get go |
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Definition
| directionality; higher; lower |
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Term
Noise:
-Because of the small size of the moving parts, microphones produce a very ___ signal. A signal must be ___ (~ x1000) to be heard. Unwanted noise will also be ___ |
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Definition
| small; amplified; amplified |
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Term
Noise:
-Dynamic microphones produce no ___ but the circuitry in condensers can create noise if not designed ___
-Noise can also be created by physical ___ through the body of the microphone
-Microphones are sensitive to ___ and ___ noise |
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Definition
| noise; properly; vibrations; wind; breath |
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