HAC Assistive Listening Device Technology 2 — Questions and Answers
Question 1: Which type of FM system transmitter is most appropriate for use in a large auditorium or lecture hall?
- Personal body-worn transmitter
- Wide-band FM transmitter
- Soundfield FM transmitter (Correct answer)
- Neck-loop transmitter
Correct answer: Soundfield FM transmitter
Soundfield FM transmitters distribute amplified sound evenly throughout a large space using multiple ceiling or wall-mounted speakers.
Question 2: A patient reports that their telecoil-equipped hearing aid picks up significant interference from fluorescent lighting. What is the most likely cause?
- Weak battery in the hearing aid
- Electromagnetic interference from the lighting ballast (Correct answer)
- Incorrect telecoil frequency setting
- Faulty microphone in the hearing aid
Correct answer: Electromagnetic interference from the lighting ballast
Fluorescent lighting ballasts emit electromagnetic fields that can be detected by telecoils and perceived as buzzing or humming interference.
Question 3: What does the HAC Act require of wireline telephones manufactured in the United States?
- They must include Bluetooth connectivity
- They must be compatible with hearing aids in microphone and telecoil modes (Correct answer)
- They must have adjustable volume up to 30 dB
- They must include a built-in FM receiver
Correct answer: They must be compatible with hearing aids in microphone and telecoil modes
The Hearing Aid Compatibility Act requires wireline telephones to be compatible with hearing aids in both acoustic (microphone) and inductive (telecoil) coupling modes.
Question 4: An infrared ALD system fails to work when a patient moves to a seat near a window with direct sunlight. What is the most likely reason?
- The receiver battery is low
- Sunlight contains infrared radiation that overwhelms the receiver (Correct answer)
- The transmitter frequency drifted
- The patient's clothing is blocking the signal
Correct answer: Sunlight contains infrared radiation that overwhelms the receiver
Infrared systems are susceptible to interference from bright light sources, including sunlight, which contains infrared wavelengths that can mask the transmitted signal.
Question 5: Which coupling method is used when a patient with a telecoil-equipped hearing aid uses a neck loop connected to an FM receiver?
- Acoustic coupling
- Direct audio input
- Inductive coupling (Correct answer)
- Radio frequency coupling
Correct answer: Inductive coupling
A neck loop creates a magnetic field around the head, and the hearing aid's telecoil picks up this field inductively.
Question 6: What is the primary advantage of Bluetooth-based ALDs over traditional FM systems for personal use?
- Greater transmission range outdoors
- Seamless connectivity with consumer electronics like smartphones (Correct answer)
- Higher sound quality in noisy environments
- Lower battery consumption in the transmitter
Correct answer: Seamless connectivity with consumer electronics like smartphones
Bluetooth ALDs pair directly with smartphones, tablets, and other consumer devices, enabling direct audio streaming without additional transmitters.
Question 7: A patient using a direct audio input (DAI) shoe on their behind-the-ear hearing aid complains of no sound from their FM receiver. What should be checked first?
- Telecoil program activation
- Secure connection of the DAI boot to the hearing aid (Correct answer)
- FM receiver battery level
- Transmitter frequency match
Correct answer: Secure connection of the DAI boot to the hearing aid
A loose or improperly seated DAI boot is the most common cause of no signal transmission, and should be verified before other troubleshooting steps.
HAC Assistive Listening Device Technology 2
Which type of FM system transmitter is most appropriate for use in a large auditorium or lecture hall?