Quiz Hearing Science

Pinna (outer ear)

The visible, cartilaginous part of the ear.  Acts as a funnel to capture sound waves and direct them towards the ear canal. Primarily contributes to sound localization in the midplane (front, back, above, below).

External Ear Canal (outer)

A tube leading to the eardrum. Provides an acoustic resonance effect, leading to sound pressure gain peaked around 2.5 kHz. This gain is crucial for hearing sensitivity in the speech frequency range.

Protects ear canal by trapping dust 

Sound Localization Cues (Outer)

Cues used for localizing sound in general are intensity and phase (time) difference. Interaural time and level differences. - sound and inensity

Tympanic Membrane (TM) (middle ear)

Eardrum. Transduces acoustic energy (air vibrations) into mechanical motion.

Auditory Ossicles (Middle ear)

Malleus, Incus, Stapes. Transduces the mechanical motion of the TM to fluid motion in the cochlea (stapes moving in and out of the oval window). Amplifies sound intensity across frequencies, with peak amplification at 1000 Hz.)

Eustachian Tube (Middle ear)

Connects the middle ear to the nasopharynx. Equalizes air pressure between the middle ear and the atmosphere.

Tympanic Muscles (Middle ear)

Tensor Tympani and Stapedius

Function- Contraction in response to loud sounds to protect the inner ear.

Scala Vestilibuli (SV) Inner Ear (cochlea)

Filled with perilymph(fluid). Connected to the oval window

Transmitting sound vibrations from the oval window to the rest of the cochlea

Scala Tympani (ST) Inner Ear (cochlea)

Filled with perilymph. Connected to the round window.

Involves its role in transmitting sound vibration to the auditory nerve via a fluid called perilymph

Scala Media (SM) / Cochlear Duct Inner Ear (cochlea)

Filled with endolymph. Contains the Organ of Corti.

To convert sound waves into electrical signals to the brain

Basilar Membrane (BM) - Inner Ear (cochlea)

Sits beneath the Organ of Corti.

Base: Narrow and stiff; resonates high frequencies (4-5 kHz). Apex: Wide and flaccid; resonates low frequencies (below 1 kHz). This is the tonotopic organization.

Organ of Corti- inner ear

Contains sensory hair cells.

Outer Hair Cells (OHCs): Enhance the vibration of the basilar membrane, providing sensitivity and frequency selectivity (Cochlear Amplifier). Inner Hair Cells (IHCs): The actual sensory transducers; convert mechanical motion into electrical signals.

Stria Vascularis- Inner ear

Produces endolymph and provides vascular supply. Maintains the positive electrical charge (+80 mV) of the endolymph.

rassiner membrane -Inner ear- cochlea

separates the scalar

Basilar Membrane - inner ear

does all the auditory stuff

What are the 3 auditory ossicles

incus, malleus, stapes

Stereocilia - inner ear

vital because on the top we have the ion channel

what is the outer ear composed of ?

outer ear canal and pinna

what is the middle ear composed of?

tymphanic membrane,auditory ossicles (malleus, incus, stapes),Eustachian tube, tymphanic muscles (Tensor Tympani and Stapedius muscles)

What is the inner ear composed of ?

Scala vestiboli SV, scala tympani ST,scala media SM, basilar/rassinar membrane, organ of corti, stria vascularis

Vestibular Apparatus - inner ear

Has 3 semi circular ducts deals with balance