In this unit, students investigate the phenomenon of sound. Their experiences introduce them to the following concepts, skills, and attitudes.

• Sounds are produced by vibrating objects and vibrating columns of air.
• Pitch and volume are two characteristics of sound.
• Changing the way an object vibrates can change the pitch and volume of the sound produced.
• Pitch is determined by the frequency of the vibrations; volume is determined by the amplitude of the vibrations.
• Changing the length, tension, or thickness of a string affects the frequency of vibration and, therefore, the pitch of the sound produced.
• The human ear has a membrane that vibrates when sound reaches it; the ear and the brain translate these vibrations into the sensation of sound.
• Sound is produced by the human vocal cords as air moves through the tightened cords.

Skills

• Performing experiments with sound.
• Describing the results of investigations with sound.
• Comparing and discussing the volume and pitch of the sounds produced.
• Communicating results through writing and with graphs.
• Reflecting on experiences with sound through writing and discussion.
• Using the results of previous experiments with sound to predict outcomes in new situations.
• Applying previously learned concepts and skills to design new sound-producing devices.
• Reading to obtain more information about sound, hearing, and the vocal cords.

Attitudes

• Developing an interest in investigating sound.
• Recognizing the importance of hearing safety.