HHMI Biointeractives: How Animals Use Sound To Communicate
In this Click & Learn interactive from Howard Hughes Medical Institute, students explore three case studies of how animals use sound to communicate: (1) Long-distance, low-frequency communication by elephants; (2) Courtship songs in closely-related finch species; (3) Use of ultrasound by echolocating bats and their moth prey. Each case study is supported by rich multimedia resources including video clips, sound analysis, spectrograph images. Can you discern the lowest-frequency elephant rumble? Can you accurately identify the sounds of two very closely related finch species? Can you sort sounds by spectrogram? Highly recommended. Allow one class period.
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The Doctors TV Show: How We Use Vocal Cords to Sing
How do the vocal cords of a professional singer look as she hits different notes? This 6-minute video features Dr. Sunil Verma, an Ear/Nose/Throat specialist at UC-Irving, as he uses a flexible laryngoscope to view the interior of the singer's larynx. The video shows very clearly what happens as the performer sings notes at various higher and lower pitches. Key Takeaway: Humans can loosen or stretch the vocal cords to make high and low pitched sounds.
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BrainStuff: Why Do Men Have Deeper Voices?
Adult male voices produce lower frequencies than adult female voices, but why is this? This 3-minute video uses simple language to explain the physiological differences between male and female vocal cord structure. Although the language is easy to understand, the authors integrated essential vocabulary (fundamental frequency, Hertz, pitch, trachea, larynx). In puberty, boys' vocal cords grow longer and thicker than girls'. The video introduces an analogy that compares vocal cords to guitar strings -- shortening the length of a guitar string by pressing a higher fret produces a higher pitch. Appropriate for middle school learners.
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