Acoustics and Sound Waves

A series of vocabulary flashcards summarizing key concepts in acoustics and sound waves based on the lecture notes.

Acoustics

The branch of physics concerned with the production, control, transmission, and reception of sound.

Sound Wave

A wave of pressure variation that travels through a medium, transmitting energy without transferring matter.

Doppler Examination

An imaging technique that utilizes the Doppler effect to measure the change in frequency of sound waves as they reflect off moving objects, typically blood.

Longitudinal Waves

Waves in which the oscillations of particles are parallel to the direction of wave propagation.

Transverse Waves

Waves in which the oscillations of particles are perpendicular to the direction of wave propagation.

Impedance

The acoustic resistance of a medium, defined as the product of density and sound velocity, Z = ρv.

Sound Pressure

The additional changing component of pressure in the medium caused by sound wave propagation, measured in pascals (Pa).

Acoustic Spectrum

The total frequencies present in a sound, including the fundamental frequency and its overtones.

Infrasonic Waves

Sound waves with frequencies below the human hearing range (below 20 Hz).

Ultrasonic Waves

Sound waves with frequencies above the human hearing range (above 20 kHz), used in various medical applications.

Cavitation

The formation and collapse of bubbles in a liquid due to changes in pressure, often exploited in ultrasonic procedures.

A-mode

A one-dimensional ultrasound measurement technique that captures amplitude data as a function of time.

B-mode

A two-dimensional ultrasound imaging technique that displays images as a series of dots representing varying brightness based on returning echo intensities.

M-mode

A mode in ultrasound that produces a motion picture showing the movement of structures over time.

Phonocardiography

A technique that records heart sounds using a microphone and provides objective analysis for diagnostics.

Lithotripsy

A medical procedure that uses shock waves to break up kidney stones or gallstones.

Equal Loudness Contours

Graphs that show the sound pressure level required to produce the same perceived loudness across different frequencies.

Weber-Fechner Law

A principle stating that perceived loudness is proportional to the logarithm of the actual intensity of the sound.