Speech Acoustics

Speech Science

Understanding of sound, sound production, and perception

Speech Production

When airflow and air pressure created by the movement of bodily anatomical structures creates a disturbance in the air that constitutes phonemes

Phoneme

Distinct units of sound that are used meaningfully in spoken language

Acoustics

Study of sound, or the physics of sound

Kinematics

Study of motion

Dynamics

The forces that cause movement

Psychoacoustics

The study of our perception of sound

Speech

The utterance of sound; oral expression; transfer of energy

Voice

Production of sounds by the vocal folds

Speed

Relationship of distance and time

Velocity

Speed of an object moving in a specific direction

Momentum

Measure of the strength of movement moving an object. Mass x Velocity

An object in motion stays in motion, and object at rest stays at rest

When force acts on an object the object accelerates in the same direction as the force

For every action there is an opposite and equal reaction

Work

When a force moves an object/particles over a distance

W= F x D

Energy

The ability to do work aka the total capacity of sound wave to do work

Power

The rate at which energy/work is expended/done

P=F x V

Kinetic energy

The energy of motion

Potential energy

Energy waiting to be released

Acceleration

The change in velocity as a function of time

Decelerating

The object has decreasing velocity

Characteristics of the 3 states of matter

Density

The amount of material packed into a given volume

D= mass/volume

Pressure (Pa)

The force exerted by the collision of air molecules against the sides of a container and the resulting opposite force exerted by the wall

P= Force x Area

Stiffness

The degree to which an object resists being deformed

Elasticity

The ability of an object to spring back to its resting shape when deforming forces are used

Uniform motion

Speed or velocity is constant

Inertia

The tendency of an object to resist change in its state of motion

Force

Anything that changes a state of motion

Solid

Maintains its shape

Liquid

Molecules slide freely; have surface tension

Gas

Molecules collide with one another

The harder you pull on something, the more it stretches

Hookes law

One newton over 1 square meter of pressure

Pascal

Centimeters of water

Sound Wave

A pressure wave that is audible to hear

How is sound produced

By a source that creates a vibration

Oscillation

Vibration

A back and forth motion

Pulse wave

Single disturbance travels through a medium

Throwing a stone into a pond

Clapping hands

Dropping a book

Longitudinal pressure waves

A series of pressure disturbances

Lower pressure regions

Rarefactions

Simple harmonic motion

Sinusoidal/Swine wave

If pattern is unchanging during simple harmonic motion

The rate at which vibrations occur or how often the pattern repeats

Measured in hertz or cycles per second

Frequency

Time between successive low or high pressure points

High frequency = small period

Low frequency = large period

Period

Intensity

Power of the sound wave

Watts per meter ²

Threshold of hearing

Faintest detectable sound to the human ear

Inverse square relationship

As sound waves soreds over large area, the power decreases

Wavelengths

Distance traveled by one cycle of vibration

Pitch is … of frequency

Loudness is … of intensity

Perception

Minimal difference between 2 sounds that can be perceived as having different loudness levels

Just noticeable difference

1db

Measures loudness as the ear hears it

A linear scale of loudness

A10 dB increase corresponds to one …