Physics of Sound Practice Flashcards

This set of vocabulary flashcards covers fundamental acoustic parameters including period, frequency, bigness parameters, wavelength, and propagation speed in various media.

Period

The time it takes a wave to vibrate a single cycle, determined by the sound source and cannot be adjusted.

Frequency

The number of particular events that occur in a specific duration of time, reported in units of per second, $1/\text{second}$, hertz, or $\text{Hz}$; it is not adjustable.

Amplitude

The “bigness” of a wave, which is directly related to power.

Power

The rate of energy transfer; unlike intensity, its output of sound is fixed and does not change.

Intensity

The concentration of energy in a sound beam, which changes based on the distance from the source.

Wavelength

The distance or length of one complete cycle measured in units of length, determined by both the sound source and medium, and is not adjustable.

Relationship between Period and Wavelength

One cycle is exactly one wavelength long; wavelength measures the physical distance of the cycle, while period measures the time it takes for that cycle to happen.

Wavelength and Frequency Relationship

An inverse relationship where a shorter wavelength results in a higher frequency (higher pitch), and a longer wavelength results in a lower frequency (low pitch).

Propagation speed

The rate at which a sound wave travels through a medium, depending on the density and stiffness of that medium.

Propagation speed of soft tissue

Approximately $1,540\text{ m/s}$.

Propagation speed of blood

Approximately $1,560\text{ m/s}$.

Propagation speed of bone

Approximately $3,500\text{ m/s}$, where stiffness overcomes density to transmit sound effectively.

Sound travel in states of matter

Sound travels fastest in solids, slower in liquids, and slowest in gases.

Stiffness

The ability of an object to resist compression; it is directly related to the speed of sound.

Density

The relative weight of a material; it is inversely related to the speed of sound.

Density and Speed Relationship

An inverse relationship meaning that as materials become denser, the speed of sound decreases.

Stiffness and Speed Relationship

A direct relationship meaning that as materials become stiffer, the speed of sound increases.

Propagation speed in Lungs

Slower speed because lungs are filled with air, making them less stiff and less dense, which makes vibrations less effective in transmitting sound.

Described in units of microseconds

Period

Described in units of Hertz

Frequency

Described in units of watts

Power

Described in units of pascals

Pressure

Described in units of g/cm³

Density

Described in units of distance

Particle Motion

Described in units of watts/cm²

Intensity

Described in units of length

Wavelength

Described in units of m/s

Propagation speed

How many acoustic parameters are there?

7

Regions of lower pressure and density

Rarefactions

Regions of higher pressure and density

Compression