Aud 4

Front 1

What are waveforms?

Back 1

Representation of sound with amplitude on the vertical axis and time on the horizontal axis.

Front 2

What is a spectrogram?

Back 2

a spectacular way to display speech sounds because they show frequency, intensity, and time.

Front 3

Pure tones or simple sounds

Back 3

Sounds that occur at just one Hz. very rare and are created by tuning forks and pure tone audiometers.

Front 4

What are complex sounds?

Back 4

sounds that occur at more than one frequency.

Front 5

What is sinusoidal motion?

Back 5

the simplest kind of sound wave motion that can occur in a medium. The wave created is a sine wave.

Front 6

What is the difference between intensity and loudness?

Back 6

intensity is objective, it can be measured. Loudness is subjective.

Front 7

What is decibel (dB)?

Back 7

A unit of measure for intensity most commonly used, which is one-tenth of a bel.

Front 8

What is logarithmic scale?

Back 8

a measurement scale based on exponents of a base number.

Front 9

What is considered a cycle of a sound wave

Back 9

one compression and one rarefaction of a sound wave.

Front 10

What is the period of a sound wave?

Back 10

The time required to complete one cycle of vibration of a sound wave.

Front 11

What is frequency?

Back 11

an objetive measure that is determined by the number of cycles over time.

Front 12

What is pitch?

Back 12

subjective, psychological correlate to frequency

Front 13

What is velocity?

Back 13

the speed at which sound travels through a medium.

Front 14

What is wavelength?

Back 14

can be defined as the length of a wave, as measured from an arbitray point on a sine wave to the same point on the next cycle of the wave.

Front 15

What is a phase?

Back 15

A particular point in the ime of a cycle. In sound, an air molecule's locatIon at given point in time during displacement, relative to the degrees of a circle.

Front 16

What is reverberation time?

Back 16

the amount of time it takes for a sound to decrease by 60 dB once the original sound has been terminated.

Front 17

What is a transducer?

Back 17

the device that converts one form of energy to another. eg. earphone or microphone.

Front 18

Sound Field Testing

Back 18

Pure tones presented through speakers testing both ears

Front 19

ECV

Back 19

ear canal volume - used in tympanometry

Front 20

daPa

Back 20

decaPascal 10 Pascals of pressure

Front 21

AD

Back 21

Auris Detra - right ear

Front 22

AS

Back 22

Auris Sinistra - left ear

Front 23

Childhood Diseases contributing to HL

Back 23

Excessive billyruben (jaundice), Measles, Mumps, Rhubella (German Measles), Chronic Otitus Media, Lyme Disease, Meningitus, MS, cytomegalovirus (a type of Herpes),

Front 24

Diseases during mother's pregnancy endangering child's hearing

Back 24

rubella, influenza, mumps, scarlet fever, cytomegalovirus (CMV a type of Herpes), Taxoplasmosis

Front 25

Autoimmune Disorders that can attack the cochlea

Back 25

Rheum Arthritis, lupus, AIDS

Front 26

Ototoxic drugs

Back 26

chemotherapeutic drugs, aminoglycosides (type of antibiotic), gentamicin, neomycin, streptomycin, kanamycin, quinine sulfate,

Front 27

WDRC

Back 27

Wide dynamic range compression

Front 28

Gain

Back 28

Output - Input in dBSPL

Front 29

OCL

Back 29

Output Compression Limiting

Front 30

Input/Gain Function I/G function

Back 30

Graphic representation of compression (I/O ratios)

Front 31

Saturation, peak clipping

Back 31

Input + Gain exceed MPO, results in peak clipping which give scratchy distortion

Front 32

Tilting

Back 32

AKA filtering, changing the frequency response (I/O ratios) often described in dB/octave, i.e. occluding might give a 6dB/oct rise.

Front 33

Matrix

Back 33

Three set ratio expressed as MPO/Peak Gain/Frequency Response (IP + G) from 500 Hz to peak. 108/30/15 means MPO=108, Peak Gain=30, IP + G (OPe) from 500Hz to the peak = 15

Front 34

Distortion, types

Back 34

Frequency components not present at IP. Harmonic Distortion has output w/ componentsthat are multiples of the IP (always higher Hz) the total of these is THD expressed as a %. Intermodulation distortion is the interaction of signals of different Hz than the IP resulting in components of higher OR lower Hz.

Front 35

Compression Ratio

Back 35

aka CR (which is NOT compression response) CR = change in IP dBSPL/change in OP dBSPL. Usually expressed showing change needed in IP to effect a 1dB change in OP, ie 2/1, 3/1, 3.6/1

Front 36

Attack Times, Release Times

Back 36

Time ecpressed in millisecond before target compression stabilizes once KP has been reached. Faster AT's and RT's reguire lower CR's or pumping will result

Front 37

AGC, AGC-I, AGC - O

Back 37

Auto Gain Control aka compression circuit - needs a level detector. AGC-I level detector placed before V/C and responds to the input not the output, thus V/C does not affect TK or CR. AGC - O has level detector after V/C so CR only activated once OP exceeds KP, thus, a V/C at + 10 will result in an KP 20dB higher than a V/C at -10dB

Front 38

Bands vs. Channels

Back 38

Frequncy bands can have the overall gain adjusted - all OP's simultaneously. Compression Channels allow for separate adjustments depending on the IP intensity.

Front 39

Compression Focus: prevent exceeding LDL without lowering MPO

Back 39

Use OCL (Output Compression Limiting) by having an AGC - O (auto gain compressor - output), set TK high with high CR's, fast AT,

Front 40

Compression Focus: fit to narrow DR, getting soft sound loud as quickly as possible but keeping moderate and loud sounds correctly ratioed

Back 40

use AGC - I (auto Gain Control - Input) , TK low,

Front 41

WDRC

Back 41

Wide dynamic range compression, compression adj. for restoring dynamic range & allowing normal loudness perception. AGC - I used giving v/c more effect, TK <50, CR's <4:1. Low TK's increase initial gain often leading to FB.

Front 42

FDRC

Back 42

Full Dynamic Range Compression, maximized DR, TK's as low as possible

Front 43

Mid-level or comfort controlled compression

Back 43

AGC-I give greater v/c control, tk ~60, CR's <5:1,

Front 44

TILL

Back 44

Treble Increased at Low Levels a breakthough single channel formula in the early 90's, outdated by multichannel technology

Front 45

ASP aka BILL

Back 45

Auto Signal Processing, bass Increase at low levels. Clamps low Hz in high dB, returns to regular bass when levels retund to low. channel formula in the early 90's, outdated by multichannel technology

Front 46

NAL -NL1

Back 46

Nat Acoustics Lan, Non-Linear-1, Goal - speech inteligability while keeping loudness perception = across Hz, calcs in conductive components, calcs in limited ability of impaired ear to extract needed speech signal especially in severe to profound losses. Depends on calcs of the diff between REUG and RECD (coupler difference). Formula give vent and tube recommendartions

Front 47

DSL

Back 47

Desired Sensation Level, Goal = re-ratio normal DR into impaired DR. I.O. graph shows linear amplification to Low input TK, compressed OP to hi input TK, and max op (output limited) above that. Basic Rx can calc from thresholds; further customization can be achieved with RECD (coupler difference), REUR, LDL, HA style and circuit compression type.

Front 48

IHAFF/VIOLA

Back 48

HAFitting Forum created Visual I/O Locator Algorythm (the common soft, medium, loud I/O profiles) They also created the Contour Test loudness scaling procedure, and the APHAB.

Front 49

APHAB

Back 49

Abbreviated Profile of Hearing Aid Benefit - a questionaire given post-fitting

Front 50

XT, TK

Back 50

Expansion Threshold, also Threshold Kneepoint = input below which signal is expanded (given more than linear amplification)

Front 51

lowTKexp vs. high Tkexp

Back 51

Low Tkexp allows more a higher gain ratio giving more speech but also more sibilance; hi Tkexp gives a quieter circuit but less speech audibility

Front 52

XR

Back 52

Expansion Ratio, calc = XR=Delta I / Delta O. If change in Input is fm 40dB to 50db, the Dlta I = 10. If change in Output is from 60 to 80, themn Delta O = 20. So the ratio is 10 over 20 or .5 or 50%. CR's are greater than 1 - the higher the number, the more the compression. XR's are less than 1 and the lower the number the greater the expansion or steeper the slope when the input is on the X axis and the output is on the Y axis

Front 53

ASHA

Back 53

Am Speech Lang & Hearing

Front 54

Tone Decay

Back 54

Measures auditory fatigue caused by VIII cranial nerve compromise. Olson-Noffsinger method: present 4K Hz at 20dB SL (20dB above TL) for one minute or until button released. If tone decays, record Hz, dB, time till decay test at 2K and refer for possible acoustic neuroma or tumor impinging VIII cranial nerve. (Okay to use 2K and 1K if loss too profound at 4K)

Front 55

Unmasked bone conduction

Back 55

Only tells if there is a combined conductive component -IT does NOT give bone thresholds

Front 56

Bone masking rule

Back 56

Must mask poorer THDs whenever better ear is 40dB lower than AC of poorer ear. (unmasked bone conduction only records THD of better cochlia - When in doubt - MASK!)

Front 57

Weber Test

Back 57

Set bone conducter to .5K and at better ear's air THD. Place in center of forehead, bone test (with masking) ear that hears less of the signal. If gap is => 15dB, test opposite ear (with masking) also. If gap => 15dB at .5,1k and 2K, refer.

Front 58

HH, BHI or BI

Back 58

Hearing Handicap, Binaural Imparement, expressed as a % derived from PTA. Every dB of loss past 25dB X 1.5 on symetrical loss. Assymetric multiply better ear's % X 5/6 and add worse ear's % X 1/6