Sound Waves and Acoustic Phonetics: Key Concepts and Measurements

Sound Wave

A mechanical wave that propagates through a medium, characterized by frequency, amplitude, and waveform.

Acoustic Phonetics

the study of the physical properties of sound

Longer wavelength

Lower frequency and pitch

Shorter Wavelength

Higher frequency and pitch

Frequency

The number of cycles of a sound wave that occur in one second, measured in Hertz (Hz) and perceived as pitch.

Amplitude

The maximum extent of a vibration which determines the loudness of a sound.

fundamental frequency

the lowest frequency of vibration of a standing wave

Simple periodic waves

Sine waves. one frequency only, a pure tone

Complex periodic waves

the sum of multiple sine waves of varying frequencies, amplitudes, and phases

Formant

A concentration of acoustic energy around a particular frequency in the speech signal, crucial for vowel quality.

Spectrogram

A visual representation of the spectrum of frequencies in a sound as they vary with time.

Harmonics

Multiples of a fundamental frequency

Pitch

The perceptual attribute of sound that allows it to be classified as relatively high or low, closely related to frequency.

Decibel (dB)

A logarithmic unit used to measure sound intensity or pressure level.

Waveform

The shape of a sound wave, representing the variation of air pressure over time.

Resonance

Affected by size, shape and material of instrument

With increasing jaw openess

F1 increases

As frontness of place increases

F2 increases