audiology

1. Auditory Nerve (CN VIII):

Sends auditory info to brainstem

2. Cochlear Nucleus:

First brainstem synapse; processes timing/intensity

3. Superior Olivary Complex:

Localizes sound via binaural input

4. Lateral Lemniscus:

Signal relay to midbrain

5. Inferior Colliculus:

Sound integration, reflexive responses

6. Medial Geniculate Body:

Thalamic relay to cortex

7. Auditory Cortex (Temporal Lobe):

Final auditory processing

• Acoustic Neuroma/Vestibular Schwannoma:

• Unilateral, slow-growing tumor; diagnosed via MRI; treated with surgery or radiation

• Auditory Neuropathy Spectrum Disorder (ANSD):

• Normal OAE, abnormal ABR; managed with amplification or CIs

• Auditory Processing Disorder (APD):

• Difficulty processing auditory info; diagnosed through behavioral tests; treated with therapy and strategies

• Age-related Central Decline:

• Affects complex processing; managed with training and amplification

Tinnitus

• Definition: Perception of sound with no external source

• Causes: Hearing loss, noise exposure, neurological

• Mechanism: Hyperactivity in central pathways

• Treatment: Sound therapy, CBT, counseling

Hyperacusis

• Definition: Heightened sensitivity to sound

• Causes: Cochlear damage, migraine, neurological

• Treatment: Sound desensitization, therapy

Vestibular System

• Anatomy: Semicircular canals, utricle, saccule

• Disorders: BPPV, Meniere’s, vestibular neuritis

• Symptoms: Vertigo, imbalance, nausea

• Tests: ENG/VNG, calorics, rotary chair

• Treatment: Vestibular rehab, repositioning maneuvers

Hearing Aids

• Function: Amplify sound

• Components: Microphone, amplifier, receiver, battery

• Candidates: Mild-profound HL

• Benefits: Improved speech understanding, access to sound

CROS/BAHA/Bone Conduction/OTC

• CROS: For unilateral deafness

• BAHA: Conductive or SSD

• OTC: Mild-moderate HL

Implantable Devices

• BAHA, Middle Ear Implants, Cochlear Implants

• Components (CI): External processor, internal electrode

• Candidates (CI): Bilateral severe-profound SNHL, limited HA benefit

Hearing Assistive Technology (HAT)

• Types: FM systems, alerting devices, captioned phones

• Use: Enhance hearing in specific settings (e.g., classrooms)

Goals of Amplification

• Improve audibility

• Support communication

• Reduce listening effort

Acoustic feedback =

Whistling from leakage

Gain =

Output – Input

Distortion =

Sound degradation

Frequency Response =

Range of amplified Hz

Output limiting =

Max dB output

• ITC

In the ear - (Mild-Moderate HL)

• RIC / receiver in the ear canal

• (Mild-Severe HL)

• BTE/ behind the ear

• (Mild-Profound HL, used in adults & children)

WHO ICF Model for DHH:

Anatomical structures:

• Cochlea, auditory nerve

WHO ICF Model for DHH:

Activity limitation:

• Difficulty understanding speech

WHO ICF Model for DHH: Participation restriction:

• Avoidance of social events

WHO ICF Model for DHH

• Personal factors:

• Age, motivation, coping style

WHO ICF Model for DHH:

• Environmental factors:

• Family support, accessibility

Counseling & Aural Rehab

• Communication strategies: e.g., face the person, reduce background noise

• Consider individual’s preferred communication style

• Use visual modalities (sign language, speechreading)

Deaf Culture & Multiculturalism

• Terminology: Person-first vs. identity-first language

• Modality: ASL, cued speech, oralism

1. Hearing Aid Components

• a. Battery = Power source

• b. Microphone = Picks up/converts sound

• c. Receiver = Converts electrical to acoustic signal

• d. Amplifier = Boosts signal strength

3. Vertigo

• a. Causes: BPPV, Meniere’s, vestibular neuritis

• b. Treatment: Repositioning, rehab, meds

4. Cochlear Implant Candidacy

• ✅ B) A person with moderately-severe to profound SNHL in both ears not benefiting from HAS

5. Difference: BAHA vs. CI

• BAHA: Bone conduction; used for conductive loss or SSD

• CI: Stimulates auditory nerve directly; used for severe SNHL

Q: What are symptoms of an acoustic neuroma?

A: Unilateral tinnitus, progressive hearing loss, poor word recognition.

Q: What is Auditory Neuropathy Spectrum Disorder (ANSD)?

A: Bilateral SNHL with present OAEs and abnormal ABR.

Q: What is Auditory Processing Disorder (APD)?

A: Normal hearing with poor speech-in-noise recognition and difficulty with auditory tasks.

Q: What causes tinnitus?

A: Hearing loss, noise exposure, neurological conditions.

Q: How is tinnitus treated?

A: Sound therapy, CBT, and counseling.

Q: What is hyperacusis?

Over-sensitivity to sound; can cause fear or annoyance.

Q: What are vestibular system components?

A: Semicircular canals, utricle, saccule.

What are common vestibular tests?

A: ENG/VNG, calorics, rotary chair.

What does a cochlear implant do?

A: Bypasses damaged cochlea to directly stimulate the auditory nerve.

What is the difference between a BAHA and a CI?

A: BAHA uses bone conduction for conductive/SSD; CI stimulates auditory nerve for SNHL.

Q: What is acoustic feedback in a hearing aid?

A: Whistling from sound leakage

Q: What does gain refer to in hearing aids?

A: Amplification level (output minus input

What does frequency response describe?

A: The range of frequencies a hearing aid amplifies.

Q: What does output limiting in hearing aids do?

A: Limits the maximum volume in dB.

Q: What is the WHO ICF model used for?

A: To assess hearing loss impact: structure, activity, participation, personal/environmental factors.

Which is preferred: ‘Deaf person’ or ‘person who is deaf’?

A: Use ‘Deaf person’ when referring to cultural identity; ‘person who is deaf’ in clinical contexts.