Hearing And Balance 1

Time

the instantaneous amplitude as a function of time

Phase is used in what notation?

Angle notation

If the wave is going up, what are the potential values of PHASE

0-180

If the wave is going down, what are the potential values of PHASE

180-360

If two waves are 90 degrees out of phase, what does that mean?

It means that one of the waves was 1/4 through its vibration cycle before the next one started.

The phase difference between two sinusoids is only the same if

The two sinusoids are of the same frequency

Complex signals

Auditory signals comprised of more than one frequency

Pure tones

sounds with a single frequency

Fourier

Developed the physical composition of complex signals

Frequency Domain

Representation of signals based on frequency components.

Time Domain

a description of the instantaneous amplitude as a function of time.

For Frequency Domain, what must you describe for a complete description?

amplitude, frequency, and starting phase

How is time domain created

By adding the instantaneous amplitudes present at each point in time.

MAP curve

minimum dB SPL that will evoke a sensation of hearing across the range of human hearing

Why do we have a MAP curve?

To have a comparison when checking if a person has hearing loss.

Threshold of audibility

Minimum sound pressure level that is capable of being detected by the human ear.

Threshold denotes the _ amount possible

smallest

What conditions is the MAP curve tested in

Under laboratory conditions using earphones

What are the subjects for MAP curve testing

Young healthy individuals with no known history of ear disease

What is the X-axis for the MAP curve

Frequency

What is the Y-axis for the MAP curve

The intensity of the frequency

Is the sensitivity the same at every frequency?

No, it varies

Why does the MAP curve show one to two standard deviations

Even people with normal hearing will vary some amount from the norm

What is a positive reaction to an auditory signal.

Raising your hand

What is a negative reaction to an auditory signal.

No response (because they did not hear it)

Performance Intensity

The relationship between the intensity level and how well a patient performs on a word recognition test is often plotted on a graph

What does the PI graph seek to find

How much intensity is needed for a patient to hear the tone 50% of the time

What is the frequency of speech sounds

250 Hz - 6,000 Hz

What is the most sensitive frequency range

1000 Hz - 4000 Hz

When does perception happen in the auditory system

The central auditory system

Coronal plane

divides body into front and back

Sagittal plane

divides body into left and right

Transverse plane

horizontal division of the body into upper and lower portions

Two major divisions of the auditory system

Peripheral and Central Auditory Pathways

What is the most lateral part of the ear

The outer ear

What is the most medial part of the ear

The inner ear

What makes up the central auditory system

The brain stem and auditory cortex

Where is the auditory cortex

The temporal lobe

What makes up the peripheral auditory system

outer, middle, and inner ear

What is the most lateral part of the auditory system

The pinna

Landmarks of the pinna

helix, concha, lobule, tragus

What is the pinna made up of?

Cartilage covered in skin

What collects or gathers sound to be channeled to more medial structures

The pinna

What aids in front to back hearing

The pinna

Why does the pinna stick out?

It aids in front to back hearing which helps you to know where a sound is coming from

How long is the external auditory canal

1-1.25 inches

What is the shape of the External Auditory Canal

It is curved with an irregular S-shape

What is the shape of the tube of the External Auditory Canal

Oval shaped

What is the lateral part of the External Auditory Canal made up of

cartilage

What fraction of the External Auditory Canal is cartilage

1/3

What is the medial part of the External Auditory Canal made up of

Bones

What fraction of the External Auditory Canal is made up of bone

2/3

Is the External Auditory Canal angled

yes, there is a slight angle

Is the External Auditory Canal more horizontal in children or adults

children.

Why does the External Auditory Canal become more angled in adulthood

The cheekbones rise which increases canal angles

Why does deeper in the ear canal hurt more

Bone is more susceptible to pain

What happens to the skin as you get deeper into the ear canal?

It gets thinner

What are the dust busters of the ear canals

The hair follicles (cilia)

What is excreted in the ear to maintain moisture

Ear wax

What maintains the pH of the ear canal

Ear wax

How does the ear canal keep some insects out

The ear wax can be noxious to some insects

What is the director of sounds

External Auditory Canal

Where does the External Auditory Canal direct sounds

To more medial structures

Is the External Auditory Canal a passive or active amplifier

passive

Passive amplifier

The ear canal amplifies the sound simply by being there

Where does the ear canal create the greatest boost in energy

at 2.7 to 3 kHz (15-20 dB)

What are the three main functions of the outer ear

Protection, Amplification, and Front/Back localization

How does the outer ear protect?

The s-curve of the ear canal makes it hard for things to get to more medial structures.

Audiology

Discipline or science involved in the prevention, identification, and remediation of individuals who are hard of hearing and/or deaf

What is an audiologist?

A person who is uniquely qualified to provide professional services related to auditory and vestibular impairments.

What qualifications does an audiologist have?

An audiologist has an academic degree, clinical training, and a license to practice and/or professional credential.

What services do audiologists provide?

Audiologists provide services related to prevention, assessment, and rehabilitation of auditory and vestibular impairments.

Audiology Licenses are awarded by the

state

Are you required to have a professional credential to practice audiology

No

What is the most common professional credential

CCC awarded by ASHA

Certification

Typically awarded by the governing body of a profession to individuals who have met certain academic and clinical requirements

Licensure

This is a permit to practice a profession, typically awarded by a state to individuals who have met a certain criteria

Central focus of audiology

The relationship between auditory impairments and disorders of communication

You have to be able to hear to acquire

spoken language

The primary function of the ear

Balance

There is evidence of people being interested in audiology going back into the

1800s

____ was a critical juncture for the development of audiology as a profession

WW2

Why was WW2 critical for audiology as a profession

Many military personnel sustained combat related hearing loss and needed someone to help with that

What technology began to emerge following WW2

transistor

What hospitals took the lead in establishing remediation programs for those with service-related hearing loss

Veteran's Administration Hospitals

Where did Raymond Carhart develop a graduate program of audiology

Northwestern university

Who worked with Carhart to coin the term audiology

Norton Camfield

In the early 50s there were less than ____ audiologists

500

In 1958 there was the first audiology

textbook

James Jerger led to the development of what in the 1960s

The development in the field of diagnostic audiology

When did audiologists begin to work with hearing aids

1978

When was the American Academy of Audiology established

1988

Is audiology an autonomous profession

Yes it can be

How many clinical hours do you need to become an audiologist

1820

How long is the externship for audiologists

12 months

What degree do audiologists need

AuD: Clinical Doctorate

School audiologist's role changes based on

The school district

What doctors do audiologists most commonly work with

ENTs or otologists

What workplace pays the most for audiologists

hospitals

Where is the highest audiologist salary

California