SPPA 4030 Speech Science 1

Physical QuantitiesGOOD LINK

http://www.isd.mel.nist.gov/projects/omacapi/Software/MeasuresAndUnits/MeasuresandUnitIntroduction.html

SPPA 4030 Speech Science 2

Physical Quantities Base quantities vs. Derived quantities

SPPA 4030 Speech Science 3

Base or Fundamental quantities

Quantities that must be measured Base measures from which all others

are derived

SPPA 4030 Speech Science 4

Selected Base Quantities

1. Distance or Length (l)

2. Mass (m)

3. Time (t)

SPPA 4030 Speech Science 5

Systems of Measure

English system: fps systemF: foot

P: pound

S: second

Metric system

cgs system

c: centimeters

g: grams

s: seconds

Metric system (System International)mks system

m: meterk: kilograms: second

SPPA 4030 Speech Science 6

What is the mass of speech structures?

Vocal folds ~ 2 grams combined!!

Lips

~ 25-50 grams eachTongue

~ 150 grams

SPPA 4030 Speech Science 7

What are typical distances moved by speech structures?

SPPA 4030 Speech Science 8

What is the typical duration of speech events?

SPPA 4030 Speech Science 9

Scalar vs. Vector quantitiesScalar quantities

Has only a magnitude

Vector quantities Includes more than one piece of information i.e. Magnitude AND direction

SPPA 4030 Speech Science 10

Area and VolumeArea 2-dimensional distance2

Volume 3-dimensional distance3

l

l

l

l

l

11

Displacement Displacement is a change in position Is a vector quantity

Has a magnitude (basic quantity of length) Has a direction

KINEMATIC FEATURES OF VERTICAL JAW MOTION

JAW

POS

ITIO

N

-40

0

40

JAW

VEL

OCIT

Y

-1000

0

1000

Jaw

ver

tical

pos

ition

Time

SPPA 4030 Speech Science 12

Velocity (v) Rate at which a quantity changes it’s value

v = x/t

where

v = velocity

x = distance

t = time

May be expressed as average velocity instantaneous velocity

Velocity units m/sec (SI) cm/sec miles/hour

Velocity vs. speed Volume velocity or flow

SPPA 4030 Speech Science 13

KINEMATIC FEATURES OF VERTICAL JAW MOTION

JAW

PO

SIT

ION

-40

0

40

JAW

VE

LO

CIT

Y

-1000

0

1000

TIMEJAW

AC

CE

LE

RA

TIO

N

Velocity (v)

SPPA 4030 Speech Science 14

Acceleration (a) Rate of change in velocity

‘speeding’ up or positive acceleration ‘slowing’ down or negative acceleration

a = v/t

where

a = acceleration

v = velocity

t = time

May be expressed as average acceleration instantaneous acceleration

Acceleration units m/sec2 (SI)

SPPA 4030 Speech Science 15

KINEMATIC FEATURES OF VERTICAL JAW MOTION

JAW

PO

SIT

ION

-40

0

40

JAW

VE

LO

CIT

Y

-1000

0

1000

TIMEJAW

AC

CE

LE

RA

TIO

N

SPPA 4030 Speech Science 16

Force (F) Is a push or a pull on an object

F = M*a

where

F = force

M = mass

a = acceleration

Force ↑ (or ↓) ↑ (or ↓) mass ↑ (or ↓) acceleration

Force units Newton (SI) dyne

SPPA 4030 Speech Science 17

Pressure (E or P) Force distributed over an area

E = F/A

where

E = pressure

F = force

A = area (x2)

Pressure units Pascal (SI) dyne/cm2

18

= area

= force

Ways to increase Pressure

SPPA 4030 Speech Science 19

Work (W)Force applied over a given distance

W = F*x

where

W = work

F = force

x = distance

Work ↑ (or ↓) ↑ (or ↓) force ↑ (or ↓) distance

Work units Joule (SI) Erg Footpound

SPPA 4030 Speech Science 20

Power (P)Power = rate at which work is done

Power (P)

P = W/t

where

P = Power

W = work

t = time

Power units Watt (SI) horsepower

SPPA 4030 Speech Science 21

Area over which power is focused Intensity is to power what pressure is to force

I = P/A

where

I = Intensity

P = Power

A = area

Intensity (I)

Intensity units watt/cm2

SPPA 4030 Speech Science 22

Resistance acoustic or aerodynamic resistance = pressure/flow

In electrical world

Ohm’s Law

R=E/I

whereR= resistanceE=voltageI=electric current

Note: voltage is an electric analog to pressure