Medical Interventions 1.3

How do frequency and amplitude affect how humans interpret sound?

Frequency = pitch (high or low sound); Amplitude = loudness (soft or loud sound).

What causes different types of hearing loss?

• Conductive: problem in outer/middle ear (blockage, damage).

• Sensorineural: damage to inner ear or cochlear nerve.

• Mixed: both types together.

How is hearing loss diagnosed?

Through hearing tests: Rinne, pure tone, and speech-in-noise tests, plus audiograms.

What interventions are available?

Hearing aids, cochlear implants, surgery, or removing blockages.

What are the bioethical concerns with cochlear implants?

Cultural identity (especially in Deaf community), consent for children, cost, and access fairness.

Explain physics of sound:

Sound = vibration that travels as waves through air; measured by frequency (Hz) and amplitude (dB).

Ear structures & functions:

• Outer ear: collects sound (pinna, auditory canal)

• Middle ear: amplifies vibrations (eardrum, ossicles)

• Inner ear: turns vibrations into nerve signals (cochlea, hair cells, cochlear nerve)

Pathway of sound:

Sound → pinna → auditory canal → eardrum → ossicles → oval window → cochlea → hair cells → cochlear nerve → brain.

Compare hearing loss types:

• Conductive: problem conducting sound (earwax, eardrum, ossicles).

• Sensorineural: nerve/hair cell damage → permanent.

Simple hearing tests:

• Rinne test: compares air vs bone conduction.

• Pure tone test: tests hearing at different frequencies.

• Speech-in-noise test: checks hearing in background noise.

Interpret audiograms:

Graph showing hearing thresholds (frequency vs loudness). Patterns reveal type/degree of loss.

Case studies:

Match symptoms + test results to damaged structures (e.g., cochlea damage = sensorineural).

Audiological careers:

Audiologist (tests/treats hearing) or Otolaryngologist (ENT doctor).

Bioethical concerns (cochlear implants):

Cultural impact, informed consent, equality, medical vs identity debate.

Recommend intervention:

Use audiogram:

• Mild conductive → hearing aid/surgery

• Severe sensorineural → cochlear implant

• Temporary blockage → medical treatment.

Sound

Vibrations through air we can hear

Frequency (Hz)

Pitch (high = many waves/sec)

Hertz (Hz)

Unit of frequency

Amplitude (dB)

Loudness of sound

Decibels (dB)

Unit of loudness

Outer ear

Collects sound

Pinna

Visible ear part; directs sound in

Auditory canal

Tube carrying sound to eardrum

Middle ear

Transfers & amplifies sound

Tympanic membrane

Eardrum; vibrates with sound

Eustachian tube

Balances air pressure

Ossicles

Malleus, incus, stapes—tiny bones moving sound

Inner ear

Changes sound to nerve signal

Cochlea

Spiral organ with hair cells

Sensory hair cells

Detect sound; send to nerve

Cochlear nerve

Carries signals to brain

Oval window

Entry to cochlea for vibrations

Vestibule

Controls balance

Vestibular nerve

Sends balance info to brain

Conductive hearing loss

Outer/middle ear problem

Sensorineural hearing loss

Inner ear/nerve damage

Rinne test

Air vs bone conduction check

Speech-in-noise test

Hearing with background noise

Pure tone test

Tests hearing with tones

Audiogram

Graph of hearing ability

Frequency threshold

Softest sound heard per frequency

Audiologist/Otolaryngologist

Hearing or ENT doctor

Hearing aid

Amplifies sound

Cochlear implant

Device that bypasses damaged ear parts