Speech Acoustics and Sound Concepts (Video Notes)

30 vocabulary flashcards based on the video notes.

Speech acoustics

The study of how speech sounds are produced, transmitted, and perceived.

Sound

A disturbance in a medium created by a vibrating source; audible as a pressure wave.

Pressure wave

A propagating fluctuation in pressure in a medium that constitutes sound.

Vibrating source

The object or organ that drives sound by oscillating (e.g., vocal folds).

Medium of transmission

The substance (air, water) through which sound travels from source to listener.

Intensity

A dimension of sound reflecting its loudness or energy per unit area.

Frequency

The number of sound pressure cycles per second; determines pitch.

Time

The temporal dimension of sound describing duration and timing.

Waveform

The graphical representation of a sound’s amplitude as a function of time.

Spectrum

The graphical representation of a sound’s energy across frequencies.

Spectrogram

A visual representation of a sound showing frequency and time with intensity.

Simple harmonic motion

Properties include Force, Elasticity, Interia

Pure tone

A sound consisting of a single frequency (a simple harmonic).

Complex sound

A sound consisting of multiple frequencies; typical of real-world sounds like speech.

Harmonics

Component frequencies that are integer multiples of the fundamental frequency.

Fundamental frequency

The lowest frequency in a harmonic series; the first harmonic.

Periodic

A signal that repeats itself over time with a stable frequency content.

Aperiodic

A signal that does not repeat periodically; energy spread over a range.

Amplitude

The height of a waveform; relates to the signal’s loudness.

Sound pressure

The pressure variation in the medium produced by a sound wave.

In-phase

Two signals whose cycles align so their peaks and troughs occur together.

90 degrees out of phase

A phase difference of 90 degrees between two signals, altering a sound.

180 degrees out of phase

A phase difference in which they cancel each other out, creating no noise.

Speech sounds by acoustic type

Classification of speech sounds according to their acoustic properties (e.g., vowels vs consonants).

Speech spectrogram

A spectrogram used to analyze and visualize speech over time.

Sine wave

A pure tone with a single frequency, representing simple harmonic motion.

Loudness

Perceived intensity of a sound, related to its amplitude and energy.

Speech is measured in these 3 main ways

Acoustically, Physiologically, Perceptually

Psychoacoustics

It is the perception of sound—the response to sounds

3 Dimensions of Sound

Frequency, Intensity, Time

Essential Constituents of Sound

Source of Energy, Vibrating Source, Medium of Transmission

Optional Constituent of Sound

Receiver of Sound

Swing Analogy

Consists of damping, a restorative force

Interference

Consists of in-phase, 90° out of phase, 180° out of phase