Lesson 8 — Pitch and frequency — Online

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 2

Pitch 

and 

Frequency

Lesson plan

• Quick recap
  
• paragraph 5.5
• Checking the homework

Learning goals

• Describe the link between pitch and frequency

• Know the range of hearing of humans and of other animals

•  Know what is meant by ultrasound

•  Explain why music instruments have distinct sounds

Recap

• Wavelength
  
• Amplitude
  
• Frequency
  

Wavelength

The length of a wave (in cm, m, km)

Amplitude

The distance from the center of the wave to the highest or lowest point (in cm, m, km)

Frequency

The amount of waves per second (in hertz, Hz)

One block is 2 cm long

wavelength

•  8 cm

Amplitude

•  2 cm

Frequency

•  2 Hz

This snapshots has a duration of 1 second 

One block is 2 cm long

wavelength

•  8 cm

Amplitude

•  2 cm

Frequency

•  2 Hz

This snapshots a duration of 1 second

This snapshots has a duration of 1 second 

(in cm, m, km)

One block is 2 cm long

wavelength

•  8 cm

Amplitude

•  2 cm

Frequency

•  2 Hz

This snapshots a duration of 1 second

This snapshots has a duration of 1 second 

One block is 2 cm long

wavelength

•  8 cm

Amplitude

•  2 cm

Frequency

•  2 Hz

This snapshots a duration of 1 second

2 Waves per second

This snapshots has a duration of 1 second 

An oscilloscope

Link

Amplification

The Amplitude of a wave...

...Determines the loudness of a sound

Pitch & frequency

Tone generator

The loudness of a sound is determined by its amplitude

The pitch of a sound is determined by its frequency

Pitch & frequency

Frequency: the amount of waves per second

 

Expressed in: Hertz (Hz)

High frequency— high pitch

Low frequency — low pitch

Which wave will create a higher pitch?

Pitch & frequency

• High frequency sound — short wavelength
• Low frequency sound — long wavelength
• The Frequency of a sound wave (pitch) does not affect the amplitude (loudness) of a sound wave.

Frequency 

Amplitude

Pitch 

Loudness

The audible range

20 Hz

20.000 Hz

Tone generator

The audible range

20 Hz

20.000 Hz

• All sound frequencies above 20.000 Hz are called Ultrasound
  

• All sound frequencies below 20 Hz are called Subsound
  

Hearing in Animals

The sound of music

Homework

5.6 workbook exercies

Learning goals

• Describe the link between pitch and frequency

• Know the range of hearing of humans and of other animals

•  Know what is meant by ultrasound

•  Explain why music instruments have distinct sounds