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Analog Hearing Aid

Converts sound into electric signals

Cannot discriminate between speech and unwanted noise

Consume a lot of power

Not compatible with mobile devices

Analog

Electrical signals generated are similar, or comparable to the sound

Digital

Sound waves are converted into numbers that are stored as binary digits (0’s and 1’s)

Digital Hearing Aids

Convert sound into digital signals (data)

Suppress background noise so speech is easier to listen

Power efficient so batteries last longer

Compatible with mobile devices so conversing is easier and clear

Microphone

Transducer that converts an audio signal to electronic signal

Amplifier

Increases intensity of sound

Receiver

Instrument that converts electrical energy into acoustic energy

Acts like a mini loudspeaker

Directional microphone

More sensitive to sound in front

Omnidirectional

Sensitive to sound coming from all directions

Gain

Describes the amount of amplification provided by an amplifier

The difference between the input and output

Behind-the-ear (BTE)

Fitting range: mild to profound

Coupling: custom ear mold

Roughly 15% of hearing aids dispensed

All electronics are housed in the hearing aid body

Tubing will need to be changed periodically

Near ear molds will be needed approximately every 5 years

Receiver-in-canal (RIC)

Fitting range: mild to moderate

Coupling: non-custom dome or custom ear mold

Roughly 70% of hearing aids dispensed

Microphone and amplifier in hearing aid body

Receiver is a speaker for output of sound

RIC

Smaller than BTE

Binaural Amplification

About 84% of patients are fit with two hearing aids

Not always appropriate option for everyone

If one ear is “unaidable”, 2 hearing aids is not appropriate

Cros hearing aid

Transmitter picks up sound from the “bad ear” and transmits sound to the good ear

BiCros hearing aids

Transmitter picks up sound from the “worst” and transmits sound to the “better” ear

Bone anchored hearing aids (BAHA)

Used for patients with conductive hearing losses and ontological conditions that prevent the use of air-conduction amplification systems

Cochlear implants (CI)

Allows for direct stimulation of the auditory nerve in the absence of viable hair cell function

Electrical array

Inserted into the cochlear implant and placed in close approximation to ganglion cells that are responsible for transmitting electrical impulses to the brain

Over-the-counter (OTC)

Direct to consumer self fitting devices for mild to moderate hearing losses

Personal sound amplification products

Used for situational hearing assistance for those that feel like their hearing loss does not warrant traditional, more expensive hearing aids

Verification

Is this working like it was designed to?

Validation

Is this doing what we want it to do?

Carhart’s goals for HA selection

Provide restoration of adequate sensitivity for speech and environmental sounds too faint to hear without hearing aids

Provide restoration, retention, or acquisition of the clarity of speech and other sounds with ordinary, relatively quiet environments

Ensure that higher intensity sounds are not amplified to an intolerable level

Telecoil (T-COIL)

Talker’s voice is picked up by a microphone and routed through wire that may run along the perimeter of a room (loop)

Assistive listening device (ALD)

Signaling or alerting units, flashing lights, vibrations, or increased sound intensity

Frequency modulated (FM) systems

Talker(s) use a microphone and the signal is transmitted to the listener

Some may need an intermediary device

Accessories and apps

Tv adapters

Tv box

Tv connector