HAC Hearing Aid Verification & Validation 2 — Questions and Answers
Question 1: Which prescriptive fitting formula is widely used for adult hearing aid verification targets?
- NAL-NL2 (National Acoustic Laboratories Non-Linear 2) (Correct answer)
- HINT (Hearing in Noise Test)
- SRT (Speech Reception Threshold)
- ABR (Auditory Brainstem Response)
Correct answer: NAL-NL2 (National Acoustic Laboratories Non-Linear 2)
NAL-NL2 is one of the most widely used prescriptive formulas for adult hearing aid fitting, calculating frequency-specific gain targets to maximize speech intelligibility while maintaining comfortable overall loudness.
Question 2: The International Outcome Inventory for Hearing Aids (IOI-HA) assesses patient outcomes across how many domains?
- 3
- 5
- 7 (Correct answer)
- 10
Correct answer: 7
The IOI-HA is a validated 7-item questionnaire covering daily use, benefit, residual activity limitations, satisfaction, residual participation restrictions, impact on others, and quality of life.
Question 3: The Real Ear Unaided Response (REUR) measures:
- The amplified output of the hearing aid at the eardrum
- The natural sound pressure resonance of the open, unaided ear canal (Correct answer)
- The maximum output of the hearing aid at high input levels
- The hearing aid gain compared to the prescriptive target
Correct answer: The natural sound pressure resonance of the open, unaided ear canal
REUR captures the natural acoustic resonance of the individual's open ear canal without any hearing aid present, establishing a baseline before amplification is introduced.
Question 4: The International Speech Test Signal (ISTS) is used during hearing aid verification to:
- Evaluate the patient's speech discrimination in noise
- Provide a standardized, speech-shaped input signal for real ear and electroacoustic measurements (Correct answer)
- Measure the patient's loudness discomfort level for speech
- Assess aided word recognition scores at different presentation levels
Correct answer: Provide a standardized, speech-shaped input signal for real ear and electroacoustic measurements
The ISTS is a multilingual, speech-spectrum signal used as a standardized input to verify hearing aid performance under conditions that closely resemble real-world speech.
Question 5: ANSI S3.22 is the standard that governs:
- Ethical guidelines and scope of practice for hearing aid dispensers
- Electroacoustic measurement specifications and tolerances for hearing aids (Correct answer)
- Licensing requirements for audiologists and hearing aid specialists
- Patient counseling protocols in hearing rehabilitation
Correct answer: Electroacoustic measurement specifications and tolerances for hearing aids
ANSI S3.22 specifies the standardized test methods, measurement conditions, and allowable tolerances for electroacoustic characteristics of hearing aids.
Question 6: Real Ear Insertion Gain (REIG) is calculated by:
- Subtracting the REUR from the REAR (REAR − REUR) (Correct answer)
- Subtracting the REAR from the REOR (REOR − REAR)
- Subtracting the REAR from the REUR (REUR − REAR)
- Subtracting the RESR from the REAR (RESR − REAR)
Correct answer: Subtracting the REUR from the REAR (REAR − REUR)
REIG equals REAR minus REUR, representing the actual gain the hearing aid inserts at the eardrum relative to the natural unaided ear canal resonance.
Question 7: Output Sound Pressure Level at 90 dB SPL (OSPL90) is verified during hearing aid fitting primarily to:
- Confirm the hearing aid's frequency response in quiet environments
- Ensure the maximum output does not exceed the patient's loudness discomfort levels (Correct answer)
- Measure the signal-to-noise ratio of the hearing aid circuitry
- Evaluate the battery current drain under high-load conditions
Correct answer: Ensure the maximum output does not exceed the patient's loudness discomfort levels
OSPL90 defines the hearing aid's maximum output, and verifying it against the patient's loudness discomfort level (LDL) prevents inadvertent over-amplification that could cause discomfort or harm.
HAC Hearing Aid Verification & Validation 2
Which prescriptive fitting formula is widely used for adult hearing aid verification targets?