Frequency & AmplitudeIntroductory Presentation

Opening Activity

In Clap On, Clap Off, we used the LEGO Sound Sensor to control when our robot moved and stopped.

Opening Activity

Answer the Following:

1. What is sound?

2. How does it travel?

3. How do we measure sound?

Review

Sound Sound is traveling energy which takes the form of regions of compressed air, soil, or whatever it’s traveling through.

Review

We measure sound by some of its properties such as:

• Wavelength• Frequency• Amplitude

Review: Wavelength

WavelengthIf someone were talking to you, Wavelength would be the distance between the regions of compacted air that their voice is creating.

Wavelength Wavelength Wavelength Wavelength

Review: Frequency

FrequencyFrequency is a measure of how many of the compacted regions, or wavelengths, pass a certain point over an interval of time.

Point

Review: Frequency

Frequency

The more wavelengths that pass in a set amount of time, the higher the frequency. The fewer wavelengths that pass in a set amount of time, the lower the frequency.

Low Frequency

High Frequency

1.5 wavelengths

3 wavelengths

Review: Frequency

We perceive frequency as the pitch of a sound. Thus, frequency determines how high or low a specific sound is.

high notes = high frequency

low notes = low frequency

Review: Frequency

So would a soprano sing high frequency notes or low frequency notes?

If you listened to a bass player would you be hearing high frequency sounds or low frequency sounds?

High frequency sounds

Low frequency sounds

Review: Amplitude

AmplitudeAmplitude, commonly referred to as volume, is a measure of how hard the compacted regions of energy are pushing into what’s in front of them.

Review: Amplitude

Amplitude

The harder they push they louder the sounds.

The softer they push, the quieter the sound.

Review: GraphingAs a refresher on how to graph results, examine the chart below created with the included data.

 Recorded Measurement

Trial 1 20

Trial 2 50

Trial 3 70

Trial 4 30

Data collected from experiment Data within a chart

Reminder

One last thing!Make sure you have speakers connected to

your computer, otherwise your robot won’t have anything to listen for.

Now you have the necessary knowledge to get started in the Frequency & Amplitude Activity.

Good Luck!