University of Wisconsin Stout | Wisconsin's Polytechnic University

You Sound Funny

In a physics demonstration (done carefully and safely), an instructor inhaled helium gas. When the instructor spoke their voice was at a very high pitch (frequency). Why did the pitch of their voice change?

• A. Helium gas is lighter than air and therefore has a faster speed than air. This faster speed results in the higher pitch voice.
• B. The Helium gas is less dense than air, and a vibrating, less dense material will produce a higher frequency than a vibrating dense material.
• C. The Helium gas actually permeates the outer layer of the vocal cord muscles, increasing their flexibility and allowing the vocal cords to vibrate more quickly, resulting in a higher pitched sound .
• D. The Helium absorbs moisture and the dryer gas produces the high pitch.

Answer