Flashcards in Sound Theory Deck (19)

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1

## In humans, what is the audible range of frequencies?

### 20Hz-20kHz.

2

## What is the speed of sound in air at normal temperatures?

### 343.2m/s.

3

## A hall being used for music recordings has its gallery supported by square-sectioned pillars. These are 0.5m by 0.5m cross-section. What frequency range of sound will be reflected from each pillar?

### Above roughly 700Hz.

4

## A note has a frequency of 200Hz. What is the frequency of the note an octave above?

### 400Hz.

5

## A note has the frequency of 200Hz. What is the frequency of the note an octave below?

### 100Hz.

6

## What is the wavelength of a 40Hz sine wave?

### 8.58m.

7

## How do you calculate wavelength (λ)?

### Wavelength (λ) = Velocity (v) / Frequency (f)

8

## How do you calculate frequency (f)?

### Frequency (f) = Velocity (v) / Wavelength (λ)

9

## When does diffraction occur?

### Diffraction only occurs to a significant effect if the wavelength is greater than the dimensions of the obstacle (the dimensions as 'seen' by the waves).

10

## What is power (P)?

### Power is the rate at which work is done or at which energy is produced or consumed.

11

## What is intensity (I)?

### Intensity is the power falling on, emitted by, or passing through a specific area.

12

## What is pressure (p)?

### Pressure is the force acting on a unit area.

13

## What is the decibel (dB)?

### The decibel is a unit of comparison of two powers, pressures, voltages, etc.

14

## What is the dB(A)?

### The dB(A) is a reasonably good approximation to most people's assessment of loudness.

15

## What is a the fundamental frequency in a musical sound?

### The fundamental frequency in a musical sound is the lowest frequency.

16

## What are harmonic frequencies?

### Harmonic frequencies are multiples of the fundamental frequency.

17

## How many semitones are there in an octave?

### 12.

18

## A note has a frequency of 200Hz. What is the frequency of the note an octave above?

### 400Hz.

19