HUMAN
RESPONDS TO
SOUND Fundamentals of Architectural
Acoustics
DAEP, JANELLA
TABLE OF CONTENTS
01 INTRODUCTION TO SOUND
02 NATURE OF SOUND
2
03 PERCEPTION OF SOUND
INTRODUCTION
TO SOUND
Sound is a result of vibration.
The vibration is produced by a
source, travels in the medium,
as a wave and is ultimately
3 sensed through the ear - drum
NATURE OF
SOUND
Sound is a longitudinal, mechanical
wave. Sound can travel through any
medium, but it cannot travel through a
vacuum
4
REPRESENTING A WAVE
We need to describe a friend by name,
height, colour, gender for identifying.
Similarly, we have to specify some qualities
that we shall call parameters, for wave
description. A wave is represented in terms
of its wavelength, amplitude, frequency
and time period. 5
PERCEPTION OF SOUND
PITCH LOUDNESS DURATION
is perceived as how "low" or "high" is perceived as how "loud" or "soft" is perceived as how "long" or
a sound is and represents the a sound is and relates to the "short" a sound is and relates to
cyclic, repetitive nature of the totalled number of auditory nerve onset and offset signals created by
vibrations that make up sound. stimulations over short cyclic time nerve responses to sounds
periods, most likely over the
duration of theta wave cycles
PERCEPTION OF SOUND
7
SPACIAL
TIMBRE SONIC TEXTURE LOCATION
is perceived as the quality of relates to the number of sound represents the cognitive placement
different sounds sources and the interaction of a sound in an environmental
between them= context; including the placement of
a sound on both the horizontal and
vertical plane,
PARTS
OF
THE
EAR
PAGARAN, JOYCE
DHENEEN
ANATOMY
OF
THE
EAR
OUTER
EAR
MIDDLE
EAR
INNER
EAR
HOW DO SOUND
TRAVEL?
PINNA (Auricle)
Ear canal
Eardrum
OSSICLES
Cochlea
Stereocilia
Stereocilia
Cochlea
Auditory nerve
NEXT..
Sensitivity of the ear
SENSITIVITY OF
THE EAR
MONDIDO, ANGELIKA
MINIMUM AUDIBLE THRESHOLD
This value for selected observers, who have
good hearing, and listening with both ears
THRESHOLD OF FEELING
As the pressureof the wave is increased,
the resulting sound becomes louder and louder until
it attains a level at which the sound can be felt
DECIBEL LEVEL
60dB – Normal conversation
85dB – Harmful, depending
on how long and how often
you are exposed to them and
whether you wear hearing
protection, such as earplugs
or earmuffs.
LOUDNESS LEVEL
Loudness can be described quantitatively in terms of another
subjective characteristic of sound, the so-called loudness level, which
itself is defined in terms of the sound pressure and frequency of a pure
tone.
PHON SCALE
• Is a unit of loudness for pure tones.
• The purpose of the phon is to provide
a standard measurement for perceived
intensity.
• The unit phon is used to indicate an
individual’s perception of loudness.
• The phon unit is not an SI unit in
metrology. As a result, phon shows
that perception of sound can be
changed by frequency.
Sone Scale
• Created to provide a linear scale
of loudness.
• a 10 phon increase in a sound
level is often perceived as a
doubling of loudness.
• 1 sone sound is defined as a
sound whose loudness is equal
to 40 phons.
OTHER FACTORS IN HEARING
Bernice Marni S. Taguilaso
Masking
to cover or to conceal
When two separate sources of sound are perceived
simultaneously. the perception of each is made more difficult by
the presence of the other.
If someone listens to a soft and a loud sound at the same time, he or she may not
hear the soft sound. The soft sound is masked by the loud sound. The loud sound
has a greater masking effect if the soft sound lies within the same frequency range
T I M E
sounds closer than 10 msec apart cannot be distinguished fromeach other, and those up to 50
msec apart are poorly distinguishedThis effect is of particular importance in the design of halls and
auditoriums, with respect to reception of echoes.
DIRECTIVITY
Directivity is important because it helps indicate how much sound will be directed
towards a specific area compared to all the sound energy being generated by a source.
REVERBERATION
it is the ear's reaction to echoes in an enclosed
spaced, giving an impression of "liveness" or " deadness".
THANKS
Effects of noise on hearing
CUIZON, JOHARAH LOU
Effects of noise on
hearing
In a world teeming with technology and incessant
entertainment opportunities, noise can
be a nuisance you cannot ignore or easily do away
with.
Loud noise can create physical and psychological
stress, reduce productivity, interfere with
communication and concentration, and contribute
to workplace accidents and injuries by making it
difficult to hear warning signals. The effects of
noise induced hearing loss can be profound,
limiting your ability to hear high frequency sounds,
understand speech, and seriously impairing your
ability to communicate.
The unit for measuring sound pressure
HOW SOUND is the decibel (dB). The eardrum is a very
thin membrane. This means that intense
DAMAGES sound pressure can make the
YOUR EAR eardrum vibrate to the point of rupture or
tear.
HOW SOUND DAMAGES YOUR EAR
When the eardrum is damaged, sound cannot be transmitted so effectively to the
internal structures of the ear hence causing hearing loss. The ossicles in the middle
ear can also be damaged by high intensity sound. Damage to the eardrum and/or
middle ear causes so-called conductive hearing loss but rarely results total loss of
hearing. However, the greatest effect of higher intensity sound is on the hair cells in
cochlea (inner ear) which results in permanent, irreversible hearing loss especially
for higher frequencies.
Noise-induced hearing loss (NIHL) can be
immediate when the damage is caused
by very high intensity sounds such as
gunshots near the ear or
NOISE explosions. More usually, NIHL results
INDUCED from prolonged exposure to higher
HEARING LOSS intensity sounds such as in a noisy factory,
being near loudspeakers at a music
festival or nightclub or, increasingly, from
listening to music at a high volume
level on a smartphone.
OTHER EFFECTS OF NOISE OTHER
THAN LOSS OF HEARING
TINNITUS
The perception of noise or ringing in the ears.
ALTERATION OF SLEEP
POOR PERFORMANCE AND LACK OF
CONCENTRATION
OVERPRODUCTION OF STRESS
HORMONES
ALTERATION OF SPEECH
FATIGUE
