Sound Waves Quiz

Sound Waves

• Sound waves are a type of mechanical wave that propagates through a medium, such as air, water, or solids.
• A cycle in a sound wave refers to one complete oscillation or vibration of the wave.

Energy and Distance

• The energy of a sound wave decreases with distance from its source, following the inverse square law.

Loudness and Amplitude

• Loudness is a perceptual dimension of sound related to the physical dimension of amplitude.
• Amplitude is the maximum displacement of a particle from its equilibrium position in a sound wave, measured in pascals (Pa).
• Sound amplitude is logarithmically related to sound pressure measured in micropascals (μPa).
• Loudness is directly related to amplitude, with higher amplitudes corresponding to greater loudness.

Frequency and Pitch

• Frequency refers to the number of oscillations or cycles per second in a sound wave, measured in hertz (Hz).
• Frequency is associated with the perceptual quality of pitch.
• Frequency is measured in terms of the number of cycles per second.
• Pitch is directly related to frequency, with higher frequencies corresponding to higher pitches.

Wavelength

• Wavelength is the distance between two consecutive points on a sound wave that are in phase with each other.
• The relationship between wavelength and frequency in a sound wave is inversely proportional, with shorter wavelengths corresponding to higher frequencies.
• Wavelength is associated with the perceptual quality of timbre.

Audibility Curve

• The audibility curve shows the minimum sound pressure level required for a sound to be audible at a given frequency.
• The absolute threshold for hearing refers to the minimum sound pressure level required for a sound to be audible.
• Auditory sensitivity is maximal in the frequency range of 2,000-5,000 Hz.

Pure Tones and Complex Sounds

• A pure tone is a sound wave with a single frequency and amplitude.
• A complex sound is a combination of multiple pure tones with different frequencies and amplitudes.
• When we hear a complex sound, we are actually perceiving the combination of its constituent sine wave components.

Fourier Analysis

• Fourier analysis is a mathematical technique used to break down complex sounds into their constituent sine wave components.
• Fourier analysis produces a spectrum of frequencies, with the lowest frequency component called the fundamental frequency.
• The fundamental frequency is the lowest frequency component in a Fourier analysis of complex sounds.
• A harmonic in a Fourier analysis is a frequency component that is an integer multiple of the fundamental frequency.

Timbre and Harmonics

• Timbre is the unique "tone color" or "sound quality" of a sound, determined by its harmonic composition.
• Timbre helps us differentiate between two sounds with the same pitch and loudness.
• The "illusion of the missing fundamental" demonstrates the role of harmonics in pitch perception, where the fundamental frequency is perceived even when it is not present in the sound.