The unit of sound level is....

This thing can produce sound by....

based on this picture, the sounds travel through the....

Sound level can be measured by....

Unwanted sound is called....

The number of vibration every second is called....

We can use ... to keep out noise

The following picture that has the highest sound level is....

The source of vibrations on the following musical instrument is....

Small vibration produce soft sounds.

The sounds level around 120-180 dB can demage our ears.

Sounds can't travel through the water.

Using noise barries, using carpets and soft cushions are some ways to keep out noise.

The longer air column makes the higher pitched sounds.

We can hear a frequency ultrasound of dolphine.

The thicker string makes the lower pitched sounds.

Guitar is an example of wind instruments.

We can shaking the tambourine to make a sounds.

We can open the door and window to keep out noise.