# Shared Flashcard Set

## Details

Chapter 5-Filtering and Electrical Impedance
Instrumentation and Electroacoustics
22
Audiology
03/17/2017

## Additional Audiology Flashcards

Term
 “___ is a measure of the opposition to the flow of alternating current through a circuit similar to the mechanical impedance that measures the velocity of a mechanical system driven by an alternating force ”
Definition
 Impedance
Term
 capacitors and inductors ___ the flow of current in an AC circuit; their reactance depends on the ___ of the flowing current. Hence, we can say capacitors and inductors ___ the free flow of electrons when connected in an AC circuit.
Definition
 oppose; frequency; impede
Term
 “The net reactance X is obtained by subtracting the ___ reactance from the ___ reactance (i.e., (XL–XC) Ω). The circuit is ___ if X > 0 and ___ if X < 0. ”
Definition
 capacitive; inductive; inductive; capacitive
Term
 -“___ is the measure of how readily the circuit allows current to flow through it and is given by the ratio of current to voltage in a circuit. ”-“Impedance (or admittance) is a ___-dependent quantity.”
Definition
Term
 “Because of their ___ selective properties, inductors and capacitors are ubiquitous, found in TV sets, radios, cell phones, hearing aids, amplifiers, assistive listening devices, audiometers, and all electrophysiologic measuring devices. Different combinations of resistors, inductors, and capacitors are used to implement passive filtering circuits that can ___ or ___ specific frequency bands in a given signal.”
Definition
 frequency; select; reject
Term
 “The frequencies to be selected or passed lie in the ___-band of the filter. The frequencies to be rejected are outside of the pass-band within the ___-band. The frequencies outside the pass-band are ___ to a level much lower than the pass-band. The frequency at which the pass-band transitions into the stop-band is called the ___ ___. ”
Definition
 pass; stop; attenuated; cutoff frequency ƒc
Term
 “There is a ___ band between the pass-band and the stop-band. The ___ of the transition band is generally taken as the cutoff frequency. The width of the transition band depends on the ___ of the filter.”
Definition
 transition; midpoint; complexity
Term
 The number of elements and the complexity of the filter increase as we try to decrease the ___ of the transition band.
Definition
 width
Term
 “A low-pass filter as the name suggests allows ___-frequency components to pass ahead to the next stage while rejecting the ___ frequency components”
Definition
 low; higher
Term
 “A ___ and a ___ connected in a particular order can be used to implement a low-pass filter (Figure 5–4). The alternating current flows through the resistor and the ___ ___ is taken across the capacitor. Thus, the load or the next processing stage is supplied with the ___ voltage across the capacitor.”[image]
Definition
 resistor; capacitor; output voltage; filtered
Term
 “We can also use a combination of a ___ and an ___ (Figure 5–6) to implement a low-pass filter. However, the manner in which they are connected will change. The alternating current from the mixed frequency voltage source v first flows through the ___ ___ into the ___ to produce a voltage drop vlpf across R. When the mixed frequency current flows into the inductance, the higher frequency components of the current are met with high reactive ___ by the inductor and are ___.”
Definition
 resistor R; inductor L; inductor L; resistor R; impedance; attenuated[image]
Term
 “Apart from the RC and RL combinations, active low-pass filters are also implemented using amplifiers to ___ the signal strength along with ___ and provide a better quality filtered signal by improving its ___ to ___ ratio.”
Definition
 boost; filtering; signal to noise
Term
 -“Low-pass filtering is used extensively to sculpt sounds for ___ music and electronic ___ ___”-“It is important to use a low-pass filter in Audiology to ensure that we obtain the best response for ___ and ___ auditory evoked potentials. The optimum response for cortical and subcortical auditory evoked potentials exists between __ to __ Hz such as late- and middle-latency response.”
Definition
 electronic; sound synthesis; cortical; subcortical; 1 to 30
Term
 “A low-pass filter is also used in assessing ___ ___ in low-frequency noise such as cafeteria noise and speech babble.”
Definition
 speech perception
Term
 When an ideal high-pass filter is connected to a mixed frequency voltage signal source, it will completely suppress all the ___-frequency components below a certain frequency called the ___ frequency, while leaving all the frequency components ___ that point unchanged. The band of frequencies that is below the cutoff frequency therefore forms the ___-band in this case and the band of frequencies above the cutoff frequency forms the pass-band”
Definition
 low; cutoff; above; stop
Term
 For a high-pass filter the capacitor is connected in series ___ the resistor and the filtered output voltage is taken across the ___. This output signal consists of high-frequency components from the input signal with the low-frequency signals ___ to a much lower level.
Definition
 before; resistor; attenuated[image]
Term
 “Just like the low-pass filter, we can also implement a high-pass filter with a ___ and an ___ combination but with reversed order of the components (Figure 5–9). The alternating current i consists of a mixed frequency voltage source v that passes through the ___ first and then into the ___. The filtered output voltage vhpf is taken across the ___.”
Definition
 resistor; inductor; resistor R; inductor L; inductor
Term
 -“High-pass filters are used in ___ systems to pass only the high frequenies to the tweeter while blocking low frequencies that can damage the tweeter circuitry. ”-They are also used to connect amplifier circuits to each other. This is called ___ ___. -High-pass filters also find application in image processing, communications, audiology, and speech pathology, in particular in systems where it is desirable to eliminate low frequencies. Example?
Definition
 music; AC coupling; hearing-aids
Term
 “for filtering out a particular band of frequencies and suppressing all the other frequencies we use what is called a ____ filter. This filter is a combination of a ____ filter and a ____ filter”
Definition
 band-pass; low-pass; high-pass
Term
 -“A band-pass filter is found in almost every device that processes ___ frequency signals”-“Band-pass filters are used in ___ ___ to synthesize electric music.”-Used to generate ___ ___ used in masking and in selected portions of auditory evoked potentials
Definition
 mixed; music synthesizers; narrowband noise (NBN)
Term
 A _____ filter blocks or stops a band of frequency components from appearing at the output
Definition
 band-reject
Term
 A special type of band-reject filter called a ___ ___ is designed to have a very narrow stop-band. It generally is used to reject ___ particular frequency or a ___ ___ of frequencies.
Definition
 notch filter; one; narrow strip[image]
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