Audiometry Quiz 2 Study Guide

Be familiar with the principles of Behavioral Observation Audiometry (BOA). For what ages is this testing strategy used?

Passive approach whereby an examiner observes changes in behavior that are time-locked to auditory signals. Infants under six months (some kids up to 2 years old).

What is Visual Reinforcement Audiometry (VRA)? How does it work and for what ages is it used?

When the infant localizes to the speech stimulus, the toy is lighted as a reward. Tester begins dropping in 10dB steps until the response level is bracketed (minimum response level- until no response is seen and then ascent until responding resumes). Age: 8 months to 2 years

Describe Play Audiometry and the appropriate age(s) for their use.

Any test in which the child is taught a play response to an auditory stimulus. Age: 2-5 year olds

Define Law of Initial Value

The state of an infant before an evaluation to test response to sound stimuli.

1. When does the CNS mature?

• 28 months (typical infant)

What is the reflex pathway in the spinal cord? Is the brain involved?

Sensory receptors in the hand send a stimulus via the afferent pathway which contains afferent neurons to the spinal cord. Afferent neurons enter the dorsal nerve root of the spinal cord. The stimulus is passed onto the efferent neuron which travels the efferent pathway to reach the effector organ in this case the muscles of the arm. As a result, the hands is quickly pulled back.

The brain is not involved in the reflex actions.

Describe the Moro and Auropalpebral reflexes?

Moro: whole body response involving extensions of both arms and legs, finger-spreading, and the head is thrown back.

Auropalpebral: quick contraction of the muscles around the eyes causing an eyeblink or a tightening of the lids if they eyes are closed. Occurs with loud sounds or a fearful event.

What are some attending behaviors?

• Eye widening, initiation or cessation of gross body movement

• Hands opening/closing, attending, eyebrow raise

• Quizzical or questioning look, searching without localizing

How can broadband signals be misleading?

Because the child may be responding to the low frequency components only

What's the problem with sound field hearing testing?

If a hearing loss is present, we must considered the responses to be from the better ear.

What is Minimum Response Level?

• Descend until no further response is seen and then ascend until responding resumes.

Why are behavior responses considered more qualitative than quantitative?

• When testing newborns, you may be really stimulating suprathreshold. You can't come away with a precise audiogram with discrete thresholds for certain frequencies

• A normal infant with a normal CNS will habituate to a sound stimulus very quickly. You have very few responses upon which to make judgement of hearing status.

• Inter and intra-subject variability of response. You may see no response at all and still be testing a normal hearing infant.

Why are pediatric tests assistants so important?

They must keep the infant's attention in the midline between stimulus presentation so that a clear localization or response that is time locked to the auditory stimulus presentation, can be adequately judged.

Describe different spondee and word recognition tests used with children.

• BOA: behavioral responses to speech stimuli in the sound field "Hi Baby!"

• VRA: Children of this age will localize to speech sounds

• Play audiometry: placing pegs in a peg board, etc. "Put it in"

Describe developmental milestones and examples.

Gross motor: using large groups of muscles to sit, stand walk, run, etc. keeping balance, changing positions

Fine motor: using hands to be able to eat, draw, dress, play, write, etc.

Language: speaking, using body language and gestures, communicating, and understanding what others say

Social/emotional: interacting with others, having relationships with family, friends, teacher, cooperating, and responding to the feelings of others

Cognitive: thinking skills, including learning, understanding, problem solving, reasoning, and remembering

What are some causes of developmental delay?

• Traumatic brain injury from accidental causes or physical abuse, infection (before, during, or after birth), growth or nutrition problems, chromosomal and genetic abnormalities, prematurity, poor maternal diet or minimal health care, child abuse, drug abuse during pregnancy, environmental toxins

Be familiar with the testing approaches for developmentally delayed individuals.

Depends on the functional age of a patient in terms of cognitive, motor, and language abilities

What are some causes of multi-disability?

40% unknown, 20% perinatal causes in which painful deliveries account for a significant part, 10% postpartum causes (meningitis, encephalitis), 30% prenatal causes (embryo and fetal conditions, deformities, genetic causes, cardiac arrest)

Describe some behaviors of those with emotional disturbance.

Aggression or self-injurious behavior, hyperactivity, withdrawal or pervasive mood of unhappiness or depression, development of physical symptoms or fears associated with personal or school problems, immaturity, inability to maintain relationships, learning difficulties

What are some causes of emotional disturbance?

Not really known, but suspected causes: heredity, brain disorder, diet, stress, family functioning, or combination.

What are some considered causes of autism spectrum disorder?

No single cause: genetics, environmental influences, early brain development differences

What are some causes of deaf-blindness?

Hereditary/chromosomal disorders, prenatal viruses, diseases, harmful chemicals, complications at birth, postnatal injuries or illnesses

How do we approach testing individuals who are deaf and blind?

• Testing has to be adapted to the skills of individuals. Some may be able to repeat words or respond with a hand raise when hearing pure tones. Very young patient: BOA for Speech Awareness Threshold. Older patients: sign using Print on Palm

Describe functional hearing loss, as well as causes for this behavior for both children and adults.

Individual complains of hearing loss but an actual hearing loss cannot be audiometrically confirmed. Adults: financial, hysteria. Children: attention

What are some tactics used to test functional patients?

Adults: begin with speech due to the inability to determine its loudness. Later, present the tones in an ascending manner. May be necessary to tell patient that the test results "do not make sense" and you won't be able to report that the results are reliable. Objective testing is typically performed.

What are some common behaviors of people faking a hearing loss?

• Repeating only 1/2 of a spondee, providing SRT that is better than the pure tone thresholds; saw tooth thresholds, total deafness in one ear with no shadow curve

What is the Stenger and how is it performed?

If a tone of two intensities (one greater than the other) is delivered to two ears of a person simultaneously, the ear which receives the tone of the higher intensity alone hears it. The patient is unaware of the tone presented more softly in the other ear. 

What is the purpose of Speech Recognition Threshold testing and how is it performed?

Purpose: pure toner cross check. SRT should match pure tone at 500, 1000, and 2000 Hz within +/- 5dB. SRT provides quick determination of the level of hearing

Performed using spondee words and the patient gets familiarized with the list. Patient then repeats the words as they get softer in 5dB increments. Needs to get ⅔ words right at the same dB to find SRT. 

What is the purpose of Word Recognition testing and how is it performed? 

Purpose: key element of audiometric evaluation. Can reflect how an auditory deficit impacts daily communication than pure tone thresholds. An indicator of retrocochlear pathology. Easiest stimulus to hear- kids respond to it first. NOTT a cross check for pure tone thresholds. Word list is used, carrier phrase “say the word.” 25 word list used, unless patient misses more than 3 words (then use 50 words).

Define Speech Awareness/Detection Thresholds. How does this measure differ from an SRT?

Performed when a patient doesn’t have enough hearing or discrimination for an SRT or WR. Task is to tell that a voice is present vs. silence. SAT will generally be 10dB better than an SRT. Used with patients who don’t speak English. 

What is rollover? What is the purpose? 

Test of differential diagnoses. 25 word list is presented at 3 progressively louder levels. PIPB function is developed. Typically, function rises as the loudness of speech signal is increased until it plateaus. If increase in loudness causes a decrease in word recognition, sight of lesion might be retrocochlear

Describe the Speech Banana and its purpose 

Shows phonemes that are spoken at certain dBs. Can show what sounds a patient is unable to hear. 

Know the advantages/disadvantages of speech stimuli delivery techniques 

Monitored live voice:

• Advantage: flexibility, suitable for elderly or children, developmentally delayed 

• Disadvantage: different delivery 

        Taped or CD: 

• Advantage: standard delivery each time 

• Disadvantage: may need to pause if patient takes long to respond

Describe types of Central Auditory Processing Disorder test materials and explain how they differ from those used for SRTs and WR. 

Filtered speech (sounds muffled)

Dichotic listening (different word in each ear) 

Speech in noise