Mixed Deck — All IHS Topics Flashcards

When using a syringe to inject impression material, the nozzle should be positioned:

Answer: Touching the otoblock before slowly withdrawing as the canal fills

Starting at the otoblock and withdrawing as the material fills prevents air pockets from being trapped behind the material as it is injected.

Reverberation time (RT60) is defined as the time required for sound pressure level to decrease by:

Answer: 60 dB after the source stops

RT60 is the time it takes for the sound energy in a room to decay by 60 dB once the sound source ceases.

The helicotrema is located:

Answer: At the apex of the cochlea connecting the two scalae

The helicotrema is the small opening at the cochlear apex where the scala vestibuli and scala tympani communicate.

What does the term 'open fit' refer to in hearing aid technology?

Answer: A fitting style where the ear canal is not fully occluded

Open fit hearing aids use a thin tube or receiver wire with a small dome that leaves the ear canal largely unoccluded, reducing the occlusion effect.

A patient who works in a noisy manufacturing environment with hearing loss should be counseled that the primary purpose of hearing protection in that setting is to:

Answer: Prevent further noise-induced hearing loss from occurring

Hearing protection in high-noise workplaces primarily prevents additional noise-induced threshold shift, not to improve communication.

The Client Oriented Scale of Improvement (COSI) is a validation tool used to measure a patient's progress with hearing aids. What is the primary characteristic that makes the COSI a patient-centered measure?

Answer: The patient identifies and prioritizes their own specific listening goals, which are then used to measure success.

The COSI is a highly patient-centered validation tool because it begins with the patient identifying up to five specific listening situations where they want to see improvement. The success of the hearing aid fitting is then evaluated based on their self-perceived progress in those personally relevant situations, rather than on a generic set of questions or objective data alone.

A patient presents with a completely occluded ear canal due to cerumen, but reports a history of ear surgery with a mastoid bowl. The most appropriate action is to:

Answer: Refer the patient to a physician

A history of ear surgery creating a mastoid bowl significantly increases the risk of complications during cerumen removal. This is a contraindication for in-office removal by a hearing instrument specialist, and the patient should be referred to a physician or otolaryngologist.

At what interaural attenuation level should a hearing specialist typically apply masking for air conduction testing?

Answer: 40 dB

Masking is generally applied when the air conduction signal in the test ear exceeds the bone conduction threshold of the non-test ear by 40 dB or more.

What should the audiology assistant check while performing a listening check?

Answer: cords and connections

During a listening check, the audiology assistant should check the cords and connections of the hearing aid. This involves inspecting the physical connections between the hearing aid components, such as the microphone, receiver, and battery compartment, to ensure that they are properly connected and functioning correctly. Any loose or faulty connections could affect the performance of the hearing aid, leading to issues with sound quality or amplification. Checking the cords and connections is an essential step in verifying that the hearing aid is operating as intended before fitting it to the patient.

A client fitted using a prescriptive formula reports that speech is clear, but certain environmental sounds, like running water or a kitchen fan, are uncomfortably loud. The initial verification was performed using only an average speech signal. What is the most appropriate next step using real-ear verification?

Answer: Measure the Real Ear Aided Response for a loud input (e.g., REAR85 or REAR90) to check the MPO setting.

The client's complaint is specific to loud sounds, not average speech. The Maximum Power Output (MPO) of the hearing aid controls the ceiling for loud inputs. The correct verification step is to measure the output in the ear using a loud input signal (like 85 or 90 dB SPL) to ensure the MPO is set to a level that is safe and comfortable for the user.

What is the key distinction between sound pressure level (SPL) and hearing level (HL)?

Answer: SPL uses a fixed physical reference (20 µPa); HL is referenced to average normal hearing thresholds that vary by frequency

SPL is referenced to a fixed pressure of 20 µPa across all frequencies, while HL adjusts for the ear's varying sensitivity so that 0 dB HL represents the average normal hearing threshold at each test frequency.

What is the primary advantage of insert earphones over supra-aural earphones in audiometry?

Answer: They increase interaural attenuation, reducing the need for masking

Insert earphones provide interaural attenuation of approximately 70–80 dB, significantly higher than supra-aural earphones, which reduces cross-hearing and masking requirements.

Hair cell stereocilia are connected at their tips by structures called:

Answer: Tip links

Tip links are fine filaments connecting the tip of each shorter stereocilium to the side of the adjacent taller one, gating mechanosensitive ion channels upon deflection.

A patient reports that their new hearing aids help in quiet but not during phone calls. The BEST immediate counseling step is to:

Answer: Demonstrate the telecoil or Bluetooth streaming feature and practice phone use in session

Most modern hearing aids include telecoil or Bluetooth connectivity specifically to improve telephone use; patient education and in-session practice are the first steps.

Damage to which nerve is responsible for sensorineural hearing loss in acoustic neuroma?

Answer: Vestibulocochlear nerve (CN VIII)

Acoustic neuromas (vestibular schwannomas) grow on CN VIII, compressing it and causing progressive sensorineural hearing loss.

During a tinnitus assessment, a specialist uses a procedure called tinnitus pitch matching. The purpose of this procedure is to:

Answer: Determine the frequency or pitch the patient perceives for their tinnitus

Tinnitus pitch matching involves presenting pure tones or narrowband noises to the patient and asking them to identify which frequency most closely matches their perceived tinnitus. This helps characterize the tinnitus and can guide sound therapy or masking choices. Loudness matching is a separate, complementary procedure.

Bluetooth-enabled hearing aids paired with a smartphone allow the user to:

Answer: Stream audio from the phone and control hearing aid settings via a companion app

Modern Made-for-Smartphone (MFi for iOS, ASHA for Android) Bluetooth hearing aids allow direct audio streaming from phones (calls, music, navigation) while typically keeping the microphone active as well (though some modes can prioritize streamed audio). Companion apps also allow the user to adjust volume, programs, and settings remotely. Bluetooth does not replace telecoils in loop-equipped public venues.

A patient works outdoors in varying weather. Which instrument characteristic should be PRIORITIZED during selection?

Answer: High IP (Ingress Protection) rating for moisture and dust resistance

A higher IP rating (e.g., IP67 or IP68) ensures the instrument resists damage from water ingress and dust exposure common in outdoor work environments.

A patient experiencing hearing aid feedback (whistling) when hugging family members should first be counseled to:

Answer: Cup their hand over the ear during hugs or remove the aid briefly

Feedback during close contact is normal; counseling the patient on simple behavioral strategies prevents unnecessary frustration.

What is the purpose of masking during pure-tone audiometry?

Answer: To prevent the non-test ear from responding to cross-heard signals

Masking introduces narrow-band noise to the non-test ear to prevent it from detecting signals intended for the test ear via cross-hearing.