Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
45 Cards in this Set
- Front
- Back
|
Output compression |
Monitors the signal after the amplifier but before the signal reaches the receiver |
|
|
The better the seal... |
The less acoustic feedback with greater amplification |
|
|
Linear amplifier |
Amplifies input signal until a natural limit is reached on the amplifier saturates/overloads causing distortion |
|
|
What disadvantages does sound field stimulation have? |
The patient cannot use a phone , a headset or a stethoscope |
|
|
What determines how much current will flow? |
The amount of electrical charge in each protons and electron |
|
|
The wider the amplification bandwidth... |
The greater the intelligibility and the less sound pressure needed to overcome a hearing loss |
|
|
The wider the amplification bandwidth... |
The greater the intelligibility and the less sound pressure needed to overcome a hearing loss |
|
|
Give advantages of CIC fittings |
*Reduction in occlusion effect, gain and fb
* increased headroom and high frequency emphasis |
|
|
The better the seal... |
The less fb with greater amplification |
|
|
The better the seal... |
The less fb with greater amplification |
|
|
What does the deeper place mic provide? |
Disruption of the ears own natural resonance to allow greater retention of the ears ability to transmit sound between 2000- 4000 mor effectively |
|
|
What both input/output compression involve the use of? |
Feedback circuit to accomphished method control |
|
|
What generates direct current |
A battery |
|
|
How is a sixty/ sixty hertz current produced? |
Electrons flow to the positive terminal until it's no longer positive. The negative terminal loses the electrons that make it negative and becomes positive causing the electron to return when the reversal happens 60 time in a second it's called sixty cycle/ sixty hertz current |
|
|
When is the SIE a practical solution? |
* more severe losses * gain without fb needed *directional Mics needed for snr * specific control of acoustics * smooth frequency response * telecoil needed |
|
|
What benefit does the added gain from the acoustic seal provide? |
Added gain of about 20 db that lets the wearer function with reduced sound pressure from the HA |
|
|
What does using larger wiring result in? |
Less current |
|
|
Electrical current/ sound pressure |
Directly proportional to the size of the voltage |
|
|
What does electrical resistance do? |
Restrict electron movement causing electrical friction between moving electrons and the stationary atom |
|
|
Longer tubing/wiring |
Emphasizes low frequency |
|
|
The smaller the tubing diameter |
The more high frequencies are reduced |
|
|
Ehat 2 functions does the acoustic seal utilized by the SIE-S instrument use? |
Gives an increase in SPL when it's in deeper especially in the high frequencies causing increased headroom
Limits acoustic fb/ protects the ear from loud sounds |
|
|
Why is the occlusion effect called that |
Because of the increase in bone conducted sound for frequencies below 2000hz when the ear is covered |
|
|
What does the deeper placed mic do? |
Disrupts ears natural resonance allowing a greater retention of the ears ability to transmit sounds between 2000-4000 he more effectively |
|
|
What determines how much current will flow? |
The amount of electrical charge in each proton and electron |
|
|
What are advantages to SIE and SIA fittings |
* cosmetic improvement *comfort of fit/final fit *same session fittings/service *less time/ no impressions * simple to use |
|
|
What benefit does the added gain from the acoustic seal provide? |
Added gain of approx 20db that lets wearer function with reduced sound pressure from the ha
Limits acoustic fb/ protection from loud sounds |
|
|
4 approaches when managing fb in hearing aids |
Fb suppression Adaptive notch filers Static notch filters Desperate the transducers |
|
|
What must the mic of a CIC be ale to do? |
Fit in the canal |
|
|
What should a ha professional consider doing if the results are going to be used for comparison purposes? |
Disable the reference mic when making the real ear aided response measurement |
|
|
What are advantages of SIA&SIE fittings |
Cosmetic improvement Comfort of fit, final fit, fit more severe losses Same session fittings Less time no impression Simple fitting |
|
|
What does the deeper placed mic do in a CUC fitting? |
Disrupts the ears natural resonance allowing greater retention of the ears ability to transmit sounds from 2000-4000 he more effectively |
|
|
Linear amplifier |
Amplifies input signals at a constant rate until a natural limit is reached on the amplifier and satuarates/overloads causing distortion |
|
|
The better the seal |
The less fb with greater anplification |
|
|
Output compression |
Monitors the signal after the amplifier and before the signal reaches the receiver |
|
|
What does a resistor offwr |
Resistance independent of frequency |
|
|
What is acoustic energy modified again by? |
The acoustic coupling of the earmd before the ear heard the sound |
|
|
Input compression |
Fb loop monitors the ha circuit just after the mic |
|
|
What does alternating current and sound booth have? |
Frequency wavelength and current |
|
|
What function does the acoustic seal in the SIE-s instrument perform? |
When deep in the canal it gives an acoustic overall increase in spl especially for higher frequency leading to increased headroom |
|
|
What does electrical energy use? |
The atom; the smallest part of any material |
|
|
What were the original small vents in open fittings intended for? |
Reduce pressure sensation concerns / produce useable low freq suppression to help high freq losses/ reduction of occlusion effect and occlusion to tubing only |
|
|
Describe how the power source behaves(ha battery) |
It acts like s pump separating and holding positive and negative charges into two separate terminals as opposite charges attract only electrons move drawing the electrons to the positive terminal creating current flow |
|
|
Electrical current |
Inversely proportional to the wire resistance of a wire or tubing |
|
|
The more tubing |
The greater the peaks and valleys in the frequency response |
