Audiology Chapter 14 – Amplification & Sensory Systems (Vocabulary)

A comprehensive set of vocabulary flashcards covering key terms, technologies, components, and concepts related to hearing aids, implantable devices, and assistive listening technologies from Chapter 14 of Introduction to Audiology.

Analog Hearing Aid

Older technology that processes sound as continuous electrical signals analogous to incoming acoustics; limited programmable features.

Digital Hearing Aid

Converts sound to binary digits, allowing computer programming, multiple memories, and precise signal processing.

Microphone (HA Component)

Input transducer that converts acoustic energy into an electrical signal inside a hearing aid.

Amplifier (HA Component)

Circuitry that increases the level of the electrical signal; can be analog or digital.

Receiver (HA Component)

Output transducer that converts the amplified electrical signal back into acoustic energy.

Acoustic Gain

Number of decibels added to the input signal by a hearing aid (output-input).

Frequency Response

Range of frequencies a hearing aid amplifies, limited by microphone, receiver, and earmold.

Feedback (Hearing Aid)

Whistling sound created when amplified output re-enters the microphone and is re-amplified.

Directionality

Microphone feature that reduces sounds from specific directions to improve signal-to-noise ratio.

Compression

Automatic gain-limiting circuitry that keeps loud sounds within the listener’s dynamic range.

Directional Microphone

Microphone system that suppresses noise from certain directions to enhance target speech.

Compression Circuit

Electronic design that reduces output for high-level inputs, preventing discomfort or damage.

Telecoil (Audiocoil)

Electromagnetic coil that receives magnetic signals from telephones or loop systems, bypassing the microphone.

Bluetooth Connectivity

Wireless protocol enabling hearing aids to connect to phones, computers, and accessories.

Electroacoustic Characteristics

Measurable properties of a hearing aid (e.g., gain, frequency response, distortion) obtained in a test box.

Output Sound-Pressure Level (OSPL90)

Maximum sound level a hearing aid can produce with 90-dB SPL input and volume full-on.

Distortion (Frequency)

Change in the frequency spectrum of the output compared with input.

Distortion (Amplitude)

Alteration of amplitude relationships between input and output signals.

Harmonic Distortion

Percentage of unwanted harmonics added by a hearing aid to the original signal.

Behind-the-Ear (BTE)

Hearing aid style that sits behind the pinna and couples to an earmold; suitable mild-profound losses.

Receiver-in-the-Canal (RIC)

Mini BTE with receiver placed in ear canal; dominant style for mild-moderate losses.

In-the-Ear (ITE)

Custom hearing aid filling the concha and canal; circuitry built into the earmold.

In-the-Canal (ITC)

Smaller custom aid fitting partly in the canal; limited power.

Completely-in-the-Canal (CIC)

Custom aid recessed fully in the canal; cosmetic, suitable mild-moderate loss.

Invisible-in-the-Canal (IIC)

Smallest custom aid placed deep in canal, invisible externally if anatomy allows.

Light-Driven Hearing Aid

Device using pulsed light to vibrate a transducer on the tympanic membrane for sound transmission.

Earmold

Custom coupler (no electronics) that directs sound from a BTE into the ear; tubing and venting affect acoustics.

Binaural Amplification

Use of two hearing aids to provide natural bilateral hearing, better localization, and reduced auditory deprivation.

CROS System

Contralateral Routing of Offside Signal: microphone on unaidable ear sends sound to normal ear.

BiCROS System

CROS arrangement where the better ear also requires amplification.

Bone-Conduction Hearing Aid

Device with vibrator on mastoid transmitting sound via bone for conductive losses or canal issues.

Transistor

Semiconductor switch/amplifier enabling miniaturization of 1950s hearing aids.

Dynamic Range (Patient)

Span between threshold of hearing and loudness discomfort level for an individual.

Probe Microphone Measure

Real-ear technique using a tiny microphone to record amplified sound in the ear canal.

Real-Ear Measures

Objective assessment of hearing aid output within the patient’s ear canal.

Functional Gain

Difference between aided and unaided sound-field thresholds; evaluates hearing aid benefit.

Validation (HA)

Patient-reported assessment of perceived benefit obtained through questionnaires or interviews.

OTC Hearing Aid

Over-the-counter device legally sold directly to adults with mild-moderate hearing loss (since 2017).

Carhart’s Goals

Four objectives for hearing aid selection: restore sensitivity, clarity in quiet and noise, and avoid over-amplification.

Cochlear Implant

Surgically implanted device that electrically stimulates the auditory nerve via an electrode array in the cochlea.

Mapping (CI)

Programming process adjusting electrical stimulation levels in a cochlear implant processor.

Implantable Bone-Conduction Device

Surgical system (abutment or magnet) transmitting sound via bone; FDA-approved age ≥5.

Middle-Ear Implant

Partially implantable device driving the ossicles mechanically; eliminates occlusion and feedback.

Auditory Brainstem Implant (ABI)

Device that stimulates cochlear nucleus for patients lacking an auditory nerve (e.g., NF2).

Assistive Listening Device (ALD)

Non-implant technology that improves audibility or awareness of sounds (e.g., TV amplifiers, alerting systems).

Hearing Assistance Technology (HAT)

Umbrella term including ALDs and classroom systems that augment hearing aids or stand alone.

Personal FM/DM System

Wireless classroom technology sending teacher’s voice directly to student’s hearing aid or receiver.

Classroom Audio Distribution (CAD)

System broadcasting teacher’s voice through room speakers to benefit all students.

Electromagnetic Loop

Wire loop creating magnetic field picked up by telecoils, reducing background noise in large venues.

Signal-to-Noise Ratio (SNR)

Level difference between desired signal and background noise; critical for speech intelligibility.

Gain (Hearing Aid Control)

User or programmed adjustment determining amplification level provided by the device.

Dynamic Range (Hearing Aid)

Output span a hearing aid must provide without distortion or discomfort.

Auditory Deprivation

Neural decline in unaided ear due to lack of stimulation when only one aid is used.

HFA (High-Frequency Average)

Average gain measured at 1000, 1600, and 2500 Hz during electroacoustic analysis.

Saturation Sound-Pressure Level (SSPL)

Synonym for OSPL90; maximum output regardless of input.

Integrated Circuit

Miniaturized electronic circuit enabling advanced processing in modern hearing aids.

Vacuum Tube Hearing Aid

Early electronic amplifier limited to tabletop size before transistor era.

Mastoid Vibrator

Receiver component of bone-conduction aids or implants placed against skull bone for stimulation.

Meaningful Auditory Integration Scale (MAIS)

Parent questionnaire assessing young children’s auditory behaviors and implant benefit.

Early Speech Perception Test (ESP)

Assessment measuring speech perception in children as young as 3 with severe-profound loss.

Lexical Neighborhood Test (LNT)

Open-set word recognition test with familiar words, used for pediatric implant/hearing aid evaluation.