IHS Earmold and Impression Techniques 4

Question 1

The acoustic bore diameter of an earmold has its greatest effect on which aspect of hearing aid performance?

Accepted Answer

High-frequency output and resonance

Answer

A larger acoustic bore diameter enhances high-frequency resonance and output, while a smaller bore rolls off high frequencies; bore modifications are a primary acoustic tuning tool.

Question 2

When a patient with a high-gain hearing aid reports persistent feedback even after earmold remake, the clinician should next consider:

Accepted Answer

Evaluating the acoustic vent size and considering a smaller or occluded vent

Answer

Acoustic vents can be a pathway for amplified sound to escape and re-enter the microphone; reducing vent size or occluding it eliminates this feedback path for high-gain fittings.

Question 3

What is the recommended mixing ratio consideration when using two-part silicone impression material?

Accepted Answer

Equal parts base and catalyst as specified by the manufacturer ensure proper polymerization

Answer

Manufacturer-specified equal-parts ratios ensure the correct chemical reaction for complete polymerization and predictable material properties; deviating from this causes incomplete curing.

Question 4

A 'trampoline' earmold is designed primarily for which patient population?

Accepted Answer

Infants and young children due to its flexible, safe material construction

Answer

Trampoline or soft, highly flexible earmolds are often recommended for young children because their ear canals change rapidly and the soft material is safer and more comfortable.

Question 5

The 'open jaw' technique for ear impressions is recommended when fitting patients with:

Accepted Answer

Behind-the-ear aids used for active individuals who talk frequently

Answer

Patients who talk or chew frequently cause significant TMJ-related ear canal shape changes; the open-jaw technique captures the ear canal in its most displaced state to prevent feedback and discomfort during use.

IHS - International Hearing Society Practice Test

IHS - International Hearing Society Practice Test

IHS Earmold and Impression Techniques 4