Hearing Instrument Selection & Fitting Flashcards

Which audiometric configuration typically requires more low-frequency gain in a hearing aid fitting?

Answer: Rising (reverse slope) low-frequency loss

A rising audiogram (better thresholds in high frequencies than low) requires more amplification in the low frequencies, which is less common and requires careful selection of hearing aid type and earmold.

What does the term 'gain' refer to in hearing aid acoustics?

Answer: The difference in decibels between the input sound level and the output sound level

Gain is the amplification added by the hearing aid, expressed in decibels (dB) as the difference between input sound pressure level (SPL) and output SPL at a given frequency.

What is the saturation sound pressure level (SSPL90) of a hearing aid?

Answer: The maximum output of the hearing aid when driven to saturation with a 90 dB SPL input

SSPL90 (also called OSPL90 or maximum output) is the maximum sound pressure level the hearing aid can produce when the input signal is 90 dB SPL, representing the upper limit of the device's output.

A patient reports that sounds are too loud in quiet environments but acceptable in noise. This suggests a problem with which hearing aid feature?

Answer: Compression ratio or threshold settings (compression kneepoint too low)

If sounds are too loud in quiet but acceptable in noise, the compression kneepoint (threshold at which compression begins) may be set too low, causing the hearing aid to compress even soft sounds excessively.

Which fitting approach is specifically designed for first-time hearing aid users to ease adaptation?

Answer: Acclimatization fitting starting below prescriptive target and gradually increasing gain

Acclimatization fitting starts new users at reduced gain targets (e.g., 70-80% of prescriptive target) and gradually increases gain over weeks to months, allowing the auditory system to adapt to amplification.

What is the purpose of a telecoil (T-coil) in a hearing aid?

Answer: To pick up electromagnetic signals from compatible phones and hearing loop systems, bypassing the microphone

A telecoil is an inductive coil that detects electromagnetic fields generated by telephones and hearing loop (induction loop) systems, providing a direct audio signal and reducing background noise pickup.