1. Find equivalents:

2. Complete the sentences:

1. Though sound travels in waves it is not.

2. Sound is created when.

3. The units of hertz (Hz) measure.

4. The limit of human hearing is.

5. Different musical instruments may.

6. Harmonics sounds only when.

7. We are able to distinguish between different sounds of the same frequency because.

3. Answer the questions:

1. Is sound included into the electromagnetic spectrum like light?

2. What does the term frequency refer to?

3. What pitches can you name?

4. How is a musical note characterized?

5. What are additional notes?

6. What set does each musical instrument have?

7. What sounds does the arrangement of the harmonics help us to distinguish?

4. Translate the text «How smartphones work» (Additional Reading) and make a report about the type of a telephone you prefer.