Loudness and Pitch

Summary

This script explains how sound waves are visualized as electrical signals on an oscilloscope, despite being longitudinal. It details how amplitude correlates with loudness and frequency with pitch. The human audible range is 20 Hz to 20 kHz, with ultrasounds above and infrasounds below. The script also covers the hearing ranges of various animals, like bats and dolphins, and mentions inaudible dog whistles for humans.

Takeaways

• 🌊 Sound waves are longitudinal, but they appear as transverse waves on an oscilloscope.
• 📊 Amplitude of a sound wave is directly related to its loudness; a larger amplitude means a louder sound.
• 🎶 The frequency of a sound wave determines its pitch; higher frequency corresponds to a higher pitch.
• 🔍 Wavelength and frequency are inversely related; shorter wavelengths have higher frequencies.
• 📏 Wavelength is measured between the same points on two different waves, such as between two peaks or two troughs.
• 👂 Humans can hear sounds in the frequency range of 20 Hz to 20 kHz.
• 🐭 Ultrasound refers to sounds above 20 kHz, which are inaudible to humans.
• 🐛 Infrasound refers to sounds below 20 Hz, also inaudible to humans.
• 🦇 Bats can hear sounds in the range of 2 kHz to 110 kHz, which includes ultrasound.
• 🐬 Other animals have different hearing ranges; for example, dolphins can hear up to 100 kHz.

Q & A

How does an oscilloscope help in viewing sound waves?

An oscilloscope helps in viewing sound waves by converting them into an electrical signal that can be visualized. Although sound waves are longitudinal, the oscilloscope displays them as if they were transverse waves, allowing for detailed analysis of wave properties.

What does the amplitude of a sound wave represent?

The amplitude of a sound wave represents the loudness of the sound. A larger amplitude indicates a louder sound, and it is measured from the midpoint to the peak or trough of the wave.

How is the pitch of a sound related to its frequency?

The pitch of a sound is directly related to its frequency. Higher frequency sound waves have a higher pitch, and vice versa.

What is the relationship between wavelength and frequency for sound waves traveling at the same speed?

For sound waves traveling at the same speed, the relationship between wavelength and frequency is inversely proportional. Shorter wavelengths correspond to higher frequencies.

How is wavelength measured in the context of sound waves?

Wavelength is measured between the same point on two different waves, such as between two peaks or two troughs, and it is measured in meters.

What is the range of frequencies that humans can hear?

Humans can hear frequencies between 20 hertz and 20,000 hertz.

What are sounds above 20,000 hertz called?

Sounds above 20,000 hertz are called ultrasound.

What are sounds below 20 hertz called?

Sounds below 20 hertz are called infrasound.

Why can't humans hear bat calls that are above 20 kilohertz?

Humans can't hear bat calls above 20 kilohertz because the upper limit of human hearing is 20,000 hertz, and these calls fall into the ultrasound range.

What is the hearing range of dogs, and how does it relate to dog whistles?

Dogs have a hearing range between 67 hertz and 45,000 hertz. Dog whistles can emit sounds above 20,000 hertz, which are within the dog's hearing range but inaudible to humans.

What is the hearing range of cats?

Cats have a hearing range between 45 hertz and 64,000 hertz.