Speech Science and Dynamic Microphones Study Guide

Vocabulary study flashcards covering acoustic period calculations, inner, middle, and outer ear anatomy, psychoacoustic principles, and dynamic microphone physics.

Period ($T$)

The time duration required for one complete cycle, calculated by dividing total time by the number of cycles (for example, $20\,\text{seconds} \div 10\,\text{cycles} = 2\,\text{seconds}$).

Cochlea

The main hearing structure in the inner ear that houses the organ of Corti.

Hair cells

Sensory cells in the inner ear that convert mechanical vibrations into neural and electrical signals.

Organ of Corti

The sensory organ of hearing located within the cochlea and supported by the basilar membrane.

Semicircular canals

Inner ear structures that primarily support balance.

Oval window

A membrane-covered opening to the cochlea that first receives vibrations from the middle ear.

Basilar membrane

An inner ear membrane that supports the organ of Corti and helps analyze frequencies.

Scala vestibuli and scala tympani

The cochlear chambers that transmit pressure waves.

High frequencies (cochlear detection)

The acoustic frequencies that are detected near the oval window of the cochlea.

Round window

The opening that relieves cochlear fluid pressure.

Ossicles

The three bones of the middle ear whose main function is to transmit and amplify vibrations to the inner ear.

Malleus

The middle ear ossicle (also known as the hammer) that carries vibration from the eardrum to the incus.

Incus

The middle ear ossicle commonly known as the anvil.

Stapes

The smallest bone in the human body, situated in the middle ear.

Tympanic membrane

Another name for the eardrum; it marks the boundary between the outer ear and the middle ear.

Eustachian tube

A passage that equalizes middle-ear pressure with outside air.

Stapedius muscle

A muscle in the middle ear that helps dampen loud sounds.

Pinna (auricle)

The visible outer ear structure outside the head that captures airborne sound waves, funnels them into the ear canal, and features ridges that help localize sound direction.

External auditory meatus

Another name for the human ear canal, which forms an S-shaped tube.

Cerumen (earwax)

A substance found in the ear canal that protects the canal, traps dust, and inhibits bacterial growth.

Psychoacoustics

The scientific study of the perception and interpretation of sound.

Pitch

The perceptual experience of frequency.

Sone

A scale used to measure perceived loudness.

Masking

The psychoacoustic phenomenon that makes a quiet sound inaudible in the presence of a louder sound.

Cocktail party effect

The auditory ability to focus on a single voice among many competing voices.

Place theory

A theory of hearing proposing that sound pitch corresponds to the specific location of vibration along the basilar membrane.

Just noticeable difference (JND)

The smallest detectable difference in pitch.

Interaural level difference

An auditory localization cue used primarily to determine the direction of high-frequency sounds.

The missing fundamental

An auditory illusion where the fundamental pitch of a sound is perceived even when the fundamental frequency is physically absent.

Doppler effect

The change in perceived pitch that occurs when a sound source is in motion relative to the listener.

Dynamic microphone

A transducer that converts sound-pressure variations into an electrical signal through electromagnetic induction.

Electromagnetic induction

The physical principle operating in a dynamic microphone, causing voltage to be generated as magnetic flux changes.

Diaphragm (dynamic microphone)

A thin membrane inside a microphone that moves when struck by sound waves.

Voice coil

A wire coil attached directly to the diaphragm in a dynamic microphone.

Magnet and pole pieces

Microphone components that provide a focused magnetic field around the moving coil.

Faraday's law

The principle stating that changing magnetic flux as the voice coil moves induces a voltage in the coil.

Phantom power requirement (dynamic mic)

Unnecessary for dynamic microphones because the moving coil generates the electrical signal directly.

Diaphragm-and-coil assembly mass

The greater moving mass of a dynamic microphone that often makes it less sensitive than a condenser microphone.

Ribbon microphone

A type of microphone that generates sound signals when a conductive ribbon moves within a magnetic field.