INTERNATIONAL HEARING SOCIETY (IHS) WRITTEN
PRACTICE EXAM QUESTIONS WITH ACCURATE
ANSWERS 2024-2025 LATEST UPDATED EDITION.
1. With normal hearing up to 2000 Hz, then thresholds of 45 dB at 3000 Hz
and 60 dB at 4000 Hz, which earmold style is most appropriate in a BTE
fitting?
• Answer: Non-occluding
• Explanation: A non-occluding (open) mold minimizes low-frequency
amplification and provides better high-frequency access—ideal for
steeply sloping, high-frequency losses.
2. If a patient has a hearing loss much greater in the high frequencies,
which earmold modification is advised?
• Answer: A very large-diameter sound channel
• Explanation: A larger bore reduces impedance and boosts high-
frequency output, helping patients with precipitous high-frequency
losses.
3. In a non-occluding earmold, the effect on low frequencies (< 750 Hz) is
that they are:
• Answer: Decreased
• Explanation: The open fitting allows low-frequency sounds to vent out,
reducing “boominess” and the occlusion effect in the patient’s own
voice.
,4. Placing an earmold in the ear canal will:
• Answer: Eliminate the natural ear-canal resonance
• Explanation: Filling the canal with an earmold removes the ear’s natural
resonant boost (~2500–3000 Hz), so hearing aid frequency response
must compensate.
5. A larger bore diameter in an earmold canal has what effect on
frequencies above 3000 Hz?
• Answer: Increases
• Explanation: Wider tubing lowers acoustic impedance at high
frequencies, allowing more high-frequency energy to reach the eardrum.
6. A BTE with 64 dB gain and an SSPL-90 of 124 dB would typically use
which style of earmold?
• Answer: Shell (occluding)
• Explanation: High-gain, high-output instruments need a snug,
occluding mold (shell) to prevent feedback and to deliver the full
prescribed gain.
7. What is the purpose of a Libby horn in hearing aids?
• Answer: Provide the patient more power with added high frequencies
• Explanation: A Libby horn (flared tubing) acoustically amplifies high
frequencies by acting as an impedance transformer.
, 8. Which earmold style is inherently non-occluding?
• Answer: Free-field (no mold, just open ear coupling)
• Explanation: In free-field fitting, sound is delivered via an open coupling
or tube without blocking the canal.
9. When otitis media is present, what earmold material and vent type is
recommended?
• Answer: Hard Lucite mold with a canal-or “V”-type vent
• Explanation: Rigid Lucite resists moisture damage; a small (“V” or
canal) vent allows pressure equalization and drainage.
10. Why use a short canal in an earmold?
• Answer: To provide more high frequencies
• Explanation: Shorter tubing and canal reduce high-frequency roll-off,
improving clarity for sloping high-frequency losses.
11. In a CROS fitting, what is used in the “good ear”?
• Answer: Non-occluding mold with a short canal
• Explanation: The good-ear side transmits sound from the bad-ear
microphone without blocking the ear canal or altering its natural
resonance.
12. Which earmold is NOT suited for high-frequency losses?
PRACTICE EXAM QUESTIONS WITH ACCURATE
ANSWERS 2024-2025 LATEST UPDATED EDITION.
1. With normal hearing up to 2000 Hz, then thresholds of 45 dB at 3000 Hz
and 60 dB at 4000 Hz, which earmold style is most appropriate in a BTE
fitting?
• Answer: Non-occluding
• Explanation: A non-occluding (open) mold minimizes low-frequency
amplification and provides better high-frequency access—ideal for
steeply sloping, high-frequency losses.
2. If a patient has a hearing loss much greater in the high frequencies,
which earmold modification is advised?
• Answer: A very large-diameter sound channel
• Explanation: A larger bore reduces impedance and boosts high-
frequency output, helping patients with precipitous high-frequency
losses.
3. In a non-occluding earmold, the effect on low frequencies (< 750 Hz) is
that they are:
• Answer: Decreased
• Explanation: The open fitting allows low-frequency sounds to vent out,
reducing “boominess” and the occlusion effect in the patient’s own
voice.
,4. Placing an earmold in the ear canal will:
• Answer: Eliminate the natural ear-canal resonance
• Explanation: Filling the canal with an earmold removes the ear’s natural
resonant boost (~2500–3000 Hz), so hearing aid frequency response
must compensate.
5. A larger bore diameter in an earmold canal has what effect on
frequencies above 3000 Hz?
• Answer: Increases
• Explanation: Wider tubing lowers acoustic impedance at high
frequencies, allowing more high-frequency energy to reach the eardrum.
6. A BTE with 64 dB gain and an SSPL-90 of 124 dB would typically use
which style of earmold?
• Answer: Shell (occluding)
• Explanation: High-gain, high-output instruments need a snug,
occluding mold (shell) to prevent feedback and to deliver the full
prescribed gain.
7. What is the purpose of a Libby horn in hearing aids?
• Answer: Provide the patient more power with added high frequencies
• Explanation: A Libby horn (flared tubing) acoustically amplifies high
frequencies by acting as an impedance transformer.
, 8. Which earmold style is inherently non-occluding?
• Answer: Free-field (no mold, just open ear coupling)
• Explanation: In free-field fitting, sound is delivered via an open coupling
or tube without blocking the canal.
9. When otitis media is present, what earmold material and vent type is
recommended?
• Answer: Hard Lucite mold with a canal-or “V”-type vent
• Explanation: Rigid Lucite resists moisture damage; a small (“V” or
canal) vent allows pressure equalization and drainage.
10. Why use a short canal in an earmold?
• Answer: To provide more high frequencies
• Explanation: Shorter tubing and canal reduce high-frequency roll-off,
improving clarity for sloping high-frequency losses.
11. In a CROS fitting, what is used in the “good ear”?
• Answer: Non-occluding mold with a short canal
• Explanation: The good-ear side transmits sound from the bad-ear
microphone without blocking the ear canal or altering its natural
resonance.
12. Which earmold is NOT suited for high-frequency losses?
