Topic 50 Flashcards

1
Q

What is sound?

A

Mechanical vibration transmitted by a medium

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2
Q

What is propagation?

A

In fluid and gases only, longitudinal waves are possible. In solids, transverse waves are possible.

Electromagnetic waves are transverse.

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3
Q

Formula proving waves are like a sinus function.

A

y = y0 cos[2π((x/λ)-(t/T))]

  • y = the displacement of an element or change of the gass*
  • t/T = f = Frequency (Height of sound)*
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4
Q

Formula to calcualte the speed of propagation

A

v = λ*f = λT

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5
Q

Which factors does the speed of sound depend on?

A

The medium

The strength of the forces among molecules

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6
Q

Speed of sound in water and air

A

Water: 1500 m/s

Air: 344 m/s

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7
Q

What is the frequency range of audible sound?

A

16Hz - 20000Hz

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8
Q

Values of Ultrasound and Infrasound

A

Ultrasound: > 20000 Hz

Infrasound: <16 Hz

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9
Q

What determines the strength of a sound?

A

Its intensity, power per unit area (W/m2)

Not to be confused with loudness

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10
Q

What are the two auditory thresholds?

A

Lowest audible intesnity = 10-12W/m2

Pain Sensation = 10 W/m2

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11
Q

What is loudness measured in?

A

Decibels (A logarithmic scale)

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12
Q

How are decibels calculated?

A

10 log (I/I0)

I = Intensity

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13
Q

Name 2 psychophysical laws

A

Weber-Fechner law

Stevens Law

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14
Q

What is the Weber-Fechner Law?

A

The intensity of sensation is proportional to the logarism of the relative intensity of the stimulus, idependent of the type of receptor.

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15
Q

What is Steven’s law?

A

The intensity of sensation is proportional to the power of the relative intensity of the stimulus

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16
Q

What is the doppler effect?

A

The observed sound depends on if the source or observer are in motion and which direction they are moving.