HC 9 Auditory perception and language
Chapter 10
In the first parts we talk about how we can hear
sounds. And the second part is about language
and language disorders.
So let’s start with our auditory system. We will
discuss the things mentioned on the slide.
Let’s start with sound waves. Sound waves is our stimulus for audition. When you look at this figure
here, you have this tuning fork and these little red dots should display air molecules. And when you
look here in B, when you press the tuning fork you have a compression of these air molecules inside
of the tuning fork but rarefication so less of these molecules outside of the tuning fork. And when
you then release the tuning fork again then you have the opposite, you have a rarefication inside the
tuning fork and a compression outside the tuning fork. And these waves of pressure produce these
changes in air molecules and these travel as sound waves.
There’s an interesting question, when you there is a three falling down in the forest and nobody is
there around, would that produce a sound? No cause it produces these waves of pressure but the
hearing is a product of our brains so if no ear is close by from human or non-human species that can
collect these waves of pressure then there is no sounds, so no noise is made.
,these sound waves have different properties. The first one is the frequency and that leads to pitch
perception. The frequency is the rate at which sound waves vibrate. And it is measures as cycles per
second in hertz (Hz). So you have here in the first one a low frequency sound wave and a high
frequency sound wave. And the low frequency sound wave leads to low pitched sounds whereas a
high frequency sound wave will lead to a high pitch sound.
The second property is amplitude and that leads to the perception of loudness. Amplitude is
measured in decibels (dB). So the intensity of sound is measured in decibels. High amplitude sound
waves lead to loud sounds. Low amplitude sound waves lead to soft sounds.
The last property is called complexity or timbre and that leads to the perception of sound quality.
When you have a tuning fork you can produce a pure tone but most of our sounds are mixtures of
frequencies. So a sound complexity determines its timbre and that allows to distinguish for example
different instruments, a trombone from a violine playing. So you have a simple tone but a complex
tone has a mixture of frequencies as you see here, low and high and low amplitude and high
amplitude. So it’s a mixture of frequencies and amplitude that leads to complex sounds.
So to sum up we have the frequency.
(reads what’s on the slide).
, You see here
the range of
frequency
that humans
and other
species can
hear.
(describes
some lines of
species:
humans,
whales and
dolphins,
dogs and
frogs)
(reads what’s on the slide)
Chapter 10
In the first parts we talk about how we can hear
sounds. And the second part is about language
and language disorders.
So let’s start with our auditory system. We will
discuss the things mentioned on the slide.
Let’s start with sound waves. Sound waves is our stimulus for audition. When you look at this figure
here, you have this tuning fork and these little red dots should display air molecules. And when you
look here in B, when you press the tuning fork you have a compression of these air molecules inside
of the tuning fork but rarefication so less of these molecules outside of the tuning fork. And when
you then release the tuning fork again then you have the opposite, you have a rarefication inside the
tuning fork and a compression outside the tuning fork. And these waves of pressure produce these
changes in air molecules and these travel as sound waves.
There’s an interesting question, when you there is a three falling down in the forest and nobody is
there around, would that produce a sound? No cause it produces these waves of pressure but the
hearing is a product of our brains so if no ear is close by from human or non-human species that can
collect these waves of pressure then there is no sounds, so no noise is made.
,these sound waves have different properties. The first one is the frequency and that leads to pitch
perception. The frequency is the rate at which sound waves vibrate. And it is measures as cycles per
second in hertz (Hz). So you have here in the first one a low frequency sound wave and a high
frequency sound wave. And the low frequency sound wave leads to low pitched sounds whereas a
high frequency sound wave will lead to a high pitch sound.
The second property is amplitude and that leads to the perception of loudness. Amplitude is
measured in decibels (dB). So the intensity of sound is measured in decibels. High amplitude sound
waves lead to loud sounds. Low amplitude sound waves lead to soft sounds.
The last property is called complexity or timbre and that leads to the perception of sound quality.
When you have a tuning fork you can produce a pure tone but most of our sounds are mixtures of
frequencies. So a sound complexity determines its timbre and that allows to distinguish for example
different instruments, a trombone from a violine playing. So you have a simple tone but a complex
tone has a mixture of frequencies as you see here, low and high and low amplitude and high
amplitude. So it’s a mixture of frequencies and amplitude that leads to complex sounds.
So to sum up we have the frequency.
(reads what’s on the slide).
, You see here
the range of
frequency
that humans
and other
species can
hear.
(describes
some lines of
species:
humans,
whales and
dolphins,
dogs and
frogs)
(reads what’s on the slide)
