Physical Aspects of Sound

Flashcards covering key vocabulary related to the physical aspects of sound, hearing, and related auditory concepts.

Hearing

The ability to perceive sound through pressure changes in the air or other medium, measurable with instruments.

Physical Definition of Sound

Pressure changes in a medium that transport energy.

Perceptual Definition of Sound

Mental experiences created by the sensory system and brain based on an analysis of physical properties.

Wave

Periodic disturbances that transport energy through a medium.

Longitudinal Wave

A mechanical wave caused by vibrating forces, creating pressure changes by packing molecules at different densities.

Speed of Sound

The speed at which sound travels through a medium, approximately 343 meters per second in air at room temperature.

Supersonic

Describing motion at speeds faster than the speed of sound.

Sonic Boom

A very loud sound caused by a shock wave formed when an object travels faster than the speed of sound.

Doppler Effect

A shift in frequency due to the motion of a sound source.

Amplitude

The difference in pressure between the high and low peaks of a sound wave, perceived as loudness.

Decibels (dB)

A logarithmic scale used to measure sound intensity.

0 dB

Defined as the human hearing threshold.

Frequency

The number of cycles of a sound wave within a given time period, measured in Hertz (Hz).

Wavelength

The distance between peaks of a sound wave.

Fourier Analysis

The process of breaking down complex sounds into their sine wave components.

Harmonics

Pure tones that are multiples of the fundamental frequency.

Loudness

The perceptual quality most closely related to the level or amplitude of an auditory stimulus.

Conductive Hearing Loss

Hearing loss occurring when bones of the middle ear fail to transmit sound waves properly.

Nerve Hearing Loss

Hearing loss resulting from damage to the cochlea, hair cells, or auditory nerve.

Presbycusis

Age-related hearing loss, primarily affecting high frequencies.

Cochlear Implant

A medical device that bypasses damaged hair cells and directly stimulates the auditory nerve.

Interaural Time Differences (ITD)

The difference in time it takes for sound to reach each ear used for sound localization.

Interaural Level Difference (ILD)

The difference in sound intensity arriving at each ear, important for localizing sound.

Cone of Confusion

A region where all sounds produce the same interaural time and level differences, complicating sound localization.

Sine wave or pure tone

The single waveform for which variation as a function of time is a sine function. In hearing research, this is sometimes referred to as a pure tone.

Spectrum

A representation of the relative energy (intensity) present at each frequency

Harmonic Spectrum

The spectrum of a complex sound in which energy is at integer multiples of the fundamental frequency

Timbre

The psychological sensation by which a listener can judge that two sounds with the same loudness and pitch are dissimilar

Phase locking

Firing of a single neuron at one distinct point in the period of a sound wave at a given frequency.

Otolith Organ

Either of two mechanical structures in the vestibular system that sense both linear acceleration and gravity

Semicircular Canal

Any of three toroidal tubes in the vestibular system that sense angular motion

Vestibular organs

Five sense organs located in the inner ear that sense head motion and head orientation with respect to gravity

Spatial Orientation

Perception of linear motion, angular motion, and tilt

Vestibulo ocular reflex

A reflex that helps keep vision clear when the vestibular system senses head movement

Utricle

One of the two otolith organs

Saccule

One of the two otolith organs

Macula

A specialized sensory area within the utricle and saccule that contains hair cells and detects linear acceleration and gravitational forces.

Octoconia

Small calcium carbonate crystals located within the maculae of the utricle and saccule that contribute to the detection of gravity and linear acceleration.

Mal de Dabarquement Syndrome

A neurological disorder characterized by a persistent sensation of movement or rocking, often occurring after a prolonged exposure to motion, such as being on a boat.

Meniere’s syndrome

A disorder of the inner ear that can lead to episodes of vertigo, hearing loss, tinnitus, and aural fullness, often caused by fluid buildup.

Angular motion

Rotational

Linear motion

Moving in one straight direction

Tilt

To attain a sloped position