Comps Adult Amplification

What hearing devices can be used for adult amplification?

• HA- NAL-NL2

• CI

• Osseointegrated devices

• FM system

what are dampers used for?

mid frequencies

What is venting used for?

low frequencies

• better LF= larger vent

What is horns used for?

high frequencies

What is the kneepoint?

input SPL point at which compression begins

what should compression ratio be under?

2.0

What is compression ratio?

changes the amount of gain, depending on the input

Output compression characteristics

• high kneepoints/high compression

• VC is before compression, and will change the gain, but not the MPO

• good for severe to profound HL

• used instead of peak clipping so that loud sounds are compressed into the dynamic range

input compression characteristics

• lower kneepoint/ lower compression ratio

• more gain is provided to softer sounds

• VC is after compression

• Affects both gain and MPO

• good for children

What is WDRC?

• compression changes from lower to higher ratio at kneepoint -no linear

• weak sounds are audible, moderate sounds are comfortable, and intense sounds are perceived as loud without causing discomfort

What is DSL 4.0 goal?

the goal is to provide max speech audibility while maintaining comfortable loudness across all input levels

• audible speech

What is DSL 5.0 goal?

The goal is to provide max speech audibility while maintaining comfortable loudness across all inputs

• but targets can be generated from estimated threshold for infants/pediatrics

What is the of NAL NL 1 goal?

speech freqs are heard equally loud

• helps to maximize speech intelligibility

• natural speech

What is the NAL NL 2 goal?

speech freqs are heard equally loud

• but reduces gain 4 dB at mid-input levels

What is frequency transposition for?

cochlear dead regions

Why do REAL ear?

• it is the gold standard of HA verification and is supported by research

• the patient may not be able to properly describe their complaints

What do you expect the speech intelligibility index SII?

expect= 70 % or higher

What is response?

is an absolute measure of output in SPL

What is gain?

is a difference measure

• the input used to generate the response had been subtracted from the response

• If input is 50 and REUR is 51, the REUG 1

How close to the loudspeaker should a patient be?

patient should be between 1 to 1.5 meters from sound source

how close does the probe tube need to be placed?

• 5mm from the eardrum to avoid standing waves and to ensure the high frequency components of the response are accurately measured

• typical length of an adult ear canal is 25mm

• use as insertion depth of 30 mm for males, 28 mm for females

• place it approx, 3-5 mm beyond hearing aid

REUR: Real ear unaided response

• provides a reference for the REIG measurement

• serves as an indicator of abnormalities of the ear canal or middle ear

• accounts for ear canal resonance changes with the hearing aid in the ear

REAR/REAG Real ear aided response

• R- frequency response of a hearing aid that is turned on and measured in the ear canal

• G- gain of the hearing instrument across frequencies measured in the ear canal

REIG real ear insertion gain

this is calculated by the system

• amount of gain provided by the hearing instrument alone

• REAG-REUG = REIG