Audiology

Audiology Defined

• Audiology is the study of hearing disorders and the rehabilitation of people with hearing impairments.
• An audiologist is a professional in research and clinical practice focusing on hearing disorders, assessment, conservation, and aural rehabilitation.

ASHA Scope of Practice

• Prevention: Promoting hearing wellness through occupational, school, and community programs.
• Identification: Detecting dysfunction in hearing, balance, and related auditory systems.
  • Includes supervision, implementation, and follow-up of newborn hearing screenings and school screenings.
• Screening: Screening for speech, orofacial, language, cognitive, and communication modalities and making appropriate referrals to speech-language pathologists (SLPs).
  • Also involves identifying populations at risk for hearing, balance, and tinnitus.
• Assessment: Conducting and interpreting behavioral, electroacoustic, and electrophysiologic methods to assess auditory, balance, and related systems.
• Rehabilitation: Fitting and dispensing hearing assistive technology and assessing candidacy for cochlear implants, including fitting.
  • Development of aural rehabilitation plans and assessment of vestibular rehabilitation needs.
  • Training and in-servicing other related professionals.
  • Participation in Individualized Education Program (IEP) and Individualized Family Service Plan (IFSP) plans.
  • Classroom assessment and management of acoustic needs and selection, installation, and evaluation of large area amplification systems.
• Advocacy/Consultation: Serving as an "audiology social worker."
• Education/Research/Administration: Involvement in education, supervision, functional outcomes, consumer satisfaction, research, scholarly activity, and participation in professional organizations (ASHA, AAA, NJSHA, etc.).
• Practice Settings:
  • Hospitals
  • MD offices
  • Community and university speech & hearing centers
  • Higher education
  • Industry
  • Schools
  • Home health (early intervention)
  • Sub-acute, rehab, and long-term care facilities

Interprofessional Collaboration (Audiology and Speech-Language Pathology)

• Spoken language is an auditory event.

Speech-Language Pathology ASHA Scope of Practice (2016)

• Definition of the Speech-Language Pathologist
• Professional Practice Domains:
  • Advocacy and outreach
  • Supervision
  • Education
  • Administration/leadership
  • Research
• Domains of Service Delivery:
  • Collaboration: SLPs share responsibility with other professionals for creating a collaborative culture and must determine if their knowledge is adequate for comprehensive patient care.
  • Counseling: Providing education, guidance, and support to individuals, families, and caregivers regarding acceptance, adaptation, and decision-making.
  • Prevention and Wellness: Involvement in activities aimed at reducing the incidence of new disorders, identifying them early, and decreasing the severity of existing disorders.
  • Screening: Expertise in screening individuals for possible communication, hearing, and/or feeding and swallowing disorders cost-effectively, including planning and conducting hearing screening programs, selecting appropriate instruments, developing procedures, analyzing results, and making referrals.
  • Assessment: Expertise in the differential diagnosis of communication and swallowing disorders.
  • Treatment: Designing speech-language services to optimize individuals’ ability to communicate and swallow, thereby improving quality of life, based on evidence-based research and best available practice standards.
  • Modalities, Technology, and Instrumentation: Using advanced instrumentation and technologies in evaluation, management, and care.
    • Maintenance of hearing aids and assistive devices is within scope, but fitting of hearing aids is outside of the scope.
  • Population and Systems: Managing populations to improve overall health & education, experience of individuals they serve ensuring intervention strategies and therapeutic goals align with the whole patient.
• Service Delivery Areas:
  • Fluency
  • Speech production
  • Language-spoken and written (listening, processing, speaking, reading, writing, pragmatics)
  • Cognition
  • Voice
  • Resonance
  • Feeding and swallowing
  • Auditory habilitation and rehabilitation

Why Collaboration is Important

• Success in healthcare, accurate diagnosis, comorbidity, academic progress, social interaction, vocation, and therapeutic progress.
• Think "Hearing First"

Utilizing ASHA as a resource

• "Best Practices" include:
  • Preferred practice patterns: Informational base for quality patient/client care.
  • Scope of practice: Outline of the parameters of each profession.
  • Guidelines: Current best practice procedures based on available evidence.
  • Position statements: Public statements of ASHA’s official stand on various issues.
  • Knowledge and skills: Required knowledge and skills for a particular area of practice.
  • Technical reports: Supporting documentation and research for an ASHA position statement.
  • Relevant papers: Supporting and related professional documents.
  • Standards/quality indicators: Documents related to certification, accreditation, and professional standards.
  • Ethics: Code of Ethics (binding on all members and certificate holders) and supporting documents.
  • Bylaws: Bylaws of ASHA, the ASHFoundation, and the ASHA PAC.
  • Website: http://www.asha.org/policy/

Evidence-Based Practice (EBP)

• Resources for EBP are available through the ASHA website:
  • http://www.asha.org/members/ebp
  • http://ncepmaps.org/
    • A guide to the steps in the EBP process
    • EBP tutorials
    • A list of evidence-based systematic reviews on a broad range of topics

People First Terminology (21st Century)

• Emphasis is placed on the individual, not the disability.
  • Use "Student with a hearing loss," "Child on the autism spectrum," or "Individual with a disability" instead of terms like "Stutterer," "Hearing Impaired," or "Mentally retarded."

Sound

• Sound is defined as "A condition of disturbance of particles in a medium…"
• Three prerequisites for sound:
  • An energy source
  • A body capable of vibration
  • A medium of transmission (e.g., air)

Characteristics of Sound

• Sound propagation involves the disturbance (pressure wave), but the medium’s particles remain predominantly fixed.
• Important physical properties of sound:
  • Mass
  • Force (Pressure)
  • Frequency
  • Intensity

Types of Sound

• Simple Sound
  • Simple harmonic motion (SHM)
  • Pure tone (single frequency) stimulus
• Complex Sound
  • More than one pure tone
  • Speech/conversation
  • White noise
  • Background noise
  • Music

Simple Harmonic Motion (SHM) Properties

• Four parameters describing SHM (e.g., pure tone) as a function of time:
  • Frequency (f): The number of complete vibratory cycles per unit time.
  • Amplitude (A): An object’s distance from rest to maximal displacement.
  • Period (p): Amount of time needed to complete one cycle of vibration.
  • Phase ($\phi$): Describes the relative timing of compressions and rarefactions of waves (how cycles relate to each other).

Wavelength

• Wavelength ($\lambda$): The spatial quantity describing a sine wave (pure tone); the physical distance of one individual cycle.
• Characteristics of the wavelength determine what we hear.

Soundwave Interference

• In/out of phase will interfere with pure tone’s simple harmonic motion
  Constructive
  Destructive
  Constructive and Complex

Sound Measurement: Intensity

• Measure of relative intensity is logarithmic
• The decibel (dB) is the unit used to measure the intensity of a sound.
  • Sound pressure level (dB SPL)
  • Hearing level (dB HL)
  • Sensation level (dB SL)
• The psychological perception of intensity is loudness.

Decibels in Sound Pressure Level (dB SPL)

• The ear is not equally sensitive to all frequencies in the range of human hearing.
• 0 dB SPL is the reference point.

Decibels in Hearing Level (dB HL)

• The reference for dB HL is dB SPL.
• 0 dB HL is "Audiometric zero."
  • Audiometric zero (0 dB HL) refers to the level of a pure tone of a given frequency that is minimally detectable (thresholds) by an average person with normal hearing.
  • Frequency | 250Hz | 500Hz | 1000Hz | 2000Hz | 4000Hz | 8000Hz
  • dBSPL | 25.5 | 11.5 | 7.0 | 9.0 | 10.5 | 12.0
  • dBHL | 0 | 0 | 0 | 0 | 0 | 0

Decibels in Sensation Level (dB SL)

• Individual to each person.
• Dependent on threshold.
• Commonly used in audiometric testing.
• How many dB SL is the equivalent of 60 dB HL?

Sound Measurement: Frequency

• Number of complete cycles that occur in 1 second time frame (cycles per second [CPS]).
• Inversely proportional to period (the time it takes to complete 1 cycle).
• $F = frac{1}{T}$ (in seconds)
• The psychological perception of frequency is pitch.
• Cycles per second (CPS) measured in Hertz.
• Also a logarithmic scale

The Audiogram

Summary

• Sound is a condition of disturbance of particles through a medium, requiring an energy source, a body capable of vibration, and a medium of transmission.
• A waveform characterizes frequency, amplitude, period, and phase.
• Simple harmonic motion results in a pure tone, which doesn't exist naturally; all other sounds are complex tones.
• The properties of sound, including mass and force, determine the characteristics of frequency and intensity.
• The psychological perception of frequency is pitch, and the psychological perception of intensity is loudness.
• Measurements of frequency (Hz) and intensity (dB) are both logarithmic.
• Decibel scales are relative to a qualifier:
  • dBSPL
  • dBHL
  • dBSL
  • dB A,B,C, etc.
• Audiometric Zero (0) is considered the minimal detectable threshold for an average person with normal hearing.

The Ear and Hearing

• Three Parts of the Human Ear:
  • Outer ear → Acoustic energy
  • Middle ear → Mechanical energy
  • Inner ear → Hydromechanical/Electrophysiological energy

The Auditory System-Anatomical Divisions

• Outer ear
• Middle ear
• Inner ear
• Neural pathways (central system)

Functional Divisions

• Conductive mechanism
• Sensory mechanism
• Central mechanism

Pathways

• Air Conduction pathway
• Bone Conduction pathway

Outer Ear Anatomy

• Pinna: aka auricle
• External auditory canal:
  • (external auditory meatus, ear canal)
• Tympanic membrane: aka ear drum

Outer Ear Physiology

• Collects and resonates sound
• Assists in sound localization
  • Provides primary cue for determination of sound source elevation
  • Assists in distinguishing sounds that arise from in front of the listener from those that arise from behind
• Functions as protective mechanism for middle and inner ears
• Sound enhancement: boosts (amplifies) high- frequency sounds in the range of 2000 to 6000 Hz.

Middle Ear Anatomy

• Inner layers of the tympanic membrane
• Middle ear cavity: filled with air
• Ossicles: ear bones; the smallest bones in the human body
  • Malleus: (aka hammer) lateral most bone of the chain; connected to the eardrum
  • Incus: (aka anvil) center bone of the chain
  • Stapes: (aka stirrup) medial most bone or the chain, rocks in and out of the oval window.
• Eustachian Tube
  • Equalizes air pressure between middle ear (ME) cavity and nasopharynx (1º function)
  • Helps to drain fluids which might accumulate in ME into nasopharynx (2º function)
• Ligaments suspend ossicular chain loosely in middle ear space, allowing for movement
• Muscles (2.)
  • Stapedius
  • Tensor tympani

Middle Ear Physiology

• Impedance mismatch transformer
  • Matches the transfer of energy between air and fluid
  • Enhances the overall loudness of the acoustic signal from the tympanic membrane to the oval window
• Equalizes pressure between middle ear cavity and nasopharynx
• Serves to protect the inner ear from intense sounds

Mismatched Impedance Transformer

• Buckling of the tympanic membrane
• Lever action of the ossicles
• Condensation effect (areal ratio)

Inner Ear Anatomy

• Consists of auditory and vestibular labyrinths
• Pathways in petrous portion of temporal bone
• Osseous labyrinth: channel in the bone
• Membranous labyrinth: soft-tissue fluid- filled channels within osseous labyrinth containing end-organs of hearing and balance
  • Auditory Labyrinth: cochlea (Sensory end-organ of hearing)
  • Vestibular Labyrinth: semicircular canals (Sensory end-organ of balance)

Cochlea-Inner Ear

• Cochlea: end organ of hearing
• Fluid-filled space within temporal bone
• Shaped like a snail shell
• Three chambers within each duct
  • Scala vestibuli: upper portion filled with perilymph
  • Scala media: middle portion filled with endolymph
  • Scala tympani: lower portion filled with perilymph

Inner Ear Anatomy (cont.)

• Basilar membrane (on floor of scala media) separates it from scala tympani
• Organ of Corti contains sensory cells of hearing
  • about 13,000 OHC altogether
  • about 3,500 IHC altogether

Inner Ear Physiology

• Displacement pattern of basilar membrane
• Wave (established along the basilar membrane) moves from the base to the apex

The Central Auditory Pathway (Ascending)

Central Auditory Physiology

• The 8th cranial nerve bundles and leaves the cochlea.
• Auditory nerve organized so that each characteristic frequency corresponds to a place within the nerve bundle (tonotopic organization)
• Information is transmitted up the brainstem to the auditory cortex in the temporal lobe for processing.
• Remember there are both afferent and efferent pathways in the central auditory system.

Tympanometry

Auditory Brainstem Response (ABR) Study

Otoacoustic Emissions (OAE’s)

Summary

• The human auditory system is comprised of the outer ear, the middle ear, the inner ear and the central auditory pathway.
• The primary anatomy of the external ear consists of the pinna, the external auditory canal and the outer 1/3 of the tympanic membrane.
• The external ear canal functions:
  • To channel sound to the tympanic membrane (ear drum).
  • To further enhance the resonance of acoustic energy collected by the pinna.
  • To physically protect the internal structures of our ears.
• The primary anatomy of the middle ear consists of the inner 2/3rds of the tympanic membrane, the ossicular chain (incus, malleus & stapes), muscles and ligaments as well as the Eustachian tube.
• The middle ear functions include:
  • The muscles of the ossicular chain function as the middle ear’s protective mechanism
  • The ligaments of the middle ear hold the ossicular chain in its place.
  • The Eustachian tube serves to provide air flow to the middle ear cavity.
  • Mismatched impedance transformer
• The primary anatomy of the inner ear consists of the cochlea (auditory system) and the semicircular canals (vestibular system).
• The primary anatomy of the cochlea consists of the scala media, scala tympani, scala vestibula, the Basilar membrane, the organ of corti, inner and outer hair cells and the tectorial membrane.
• The inner ear functions to:

The Case History Form

• Commercially Available or Made on site
• Discipline specific and Age specific
  • Infant/toddler
  • School age
  • Adult
  • Geriatric

Prenatal History

• Maternal infections (Prenatal)
  • Gestational diabetes
  • Cytomegalovirus (CMV) infection
  • Rubella (germen measles)
  • Toxemia
  • Herpes simplex virus
  • HIV/AIDS
  • RH incompatibility factor
  • Substance abuse [fetal alcohol syndrome disorder (FASD)]

Peri- and Postnatal History

• Prematurity
• Low birth weights
• Lack of oxygen
• Prolonged labor
• Jaundice
• Complications and infections that occur as a result of CMV, Rh incompatibility factor, HIV/AIDS, and venereal diseases

History or Record Review for Newborn Hearing Screening

• What type of testing was done?
• When was the testing done?
• Did the child pass?
• Did the child fail?
• What was the recommendation for follow-up?

Family History

• 75% of congenital hearing loss, or hearing loss present at birth, is genetic in origin
• Familial history of hearing loss or other communication disorder.
• Family history of late-onset hearing loss can also be genetic in origin

Toddlers and Young Children

• History of ear infections
• Allergies
• Medications
• History of trauma
• Surgical treatment
• Seizure disorder
• Childhood illness

Toddlers and Young Children(cont.)

• Behaviors of inattentiveness
• Listening to T.V. “too loud”
• Difficulty responding to questions

Toddlers and Young Children(cont)

• Inability to accurately following directions
• Any academic and/or reading problems in school
• Excessive noise exposure (smart phones, music concerts, etc.)

School-Age Child

• Teacher interview
• Hearing inventories (school and home)
• Classroom work samples

School Age Child (cont.)

• Child Study Team input
• Review a copy of the individual education plan (IEP) or individual family service plan (IFSP)
• Have the child write: “3 Wishes”

Adults/Geriatrics (Hearing Status)

• Can the patient describe the hearing problems and other accompanying symptoms they may be experiencing?
• How long has the difficulty been noticed?
• Was the onset of hearing loss sudden or gradual?

Adults/Geriatrics (Hearing Status) cont.

• Does the onset appear to have been connected with another trauma or event?
• What are the situations that present the most and least amount of difficulty for the person?

Adults/Geriatrics (Hearing Status)(cont.)

• Does the person use a hearing aid or assistive device?
• Is the device functioning properly, does the person benefit from using the device?
• Is there a history of Occupational, recreational noise exposure?

Adults/Geriatrics (Hearing Status) cont.

• Is there a familial history of late-onset hearing loss?
• Do they experience dizziness, headaches, or any other abnormal symptom?

Adults/Geriatrics (Medical History)

• What are current and past medications with dosages, including any over-the counter and herbal supplements?
• Does the patient have diabetes?
• High cholesterol?
• Hypertension?

Adults/Geriatrics (Medical History) cont.

• Is there a history of stroke, TIA, accidents, or other trauma?
• Is there a history of a serious health condition requiring ototoxic medication with long-term hospitalization, or cancer treatments?

Informal Observation

• Look, Play, Listen
• Look:
  • Can the patient (infant, child, or adult) make eye contact?
  • Are their facial features symmetrical?
  • Are they well-groomed? Is hygiene an obvious issue?
  • Is there motor restlessness (fidgety, squirmy, ticks, etc.)?
  • Are there self-stimulation behaviors?
  • Syndromic characteristics?

Syndromic Characteristics – The Top 5 List

Trisomy 21 (AKA: Down Syndrome)
CHARGE Syndrome
Goldenhar Syndrome
Waardenburg Syndrome
Fetal Alcohol Syndrome

Informal Observation Infants/ Toddlers/ School Age

• Play (Infants/Toddlers/School Age)
  • Can the child interact with you?
  • How are their gross motor and fine motor skills?
  • Are play skills age appropriate?

Informal Observation Listen

• Look, Play, Listen
• Listen
  • How clear is their articulation?
  • Does the patient know their name?
  • Are receptive and expressive language skills age-appropriate?

Informal Observation

• Not just limited to children
• How clear is their articulation?
• Does the patient know their name?
• Are receptive and expressive language skills age appropriate?

Things to remember

• Don’t assume all information is accurate
  • “According to the caretaker…”
  • “Mrs. Smith reports…”
  • “Mr. Jones was a reticent historian regarding…”
  • “The patient revealed…”

Always confirm the relationship

• Things may not be as they seem.

Summary

• Taking a case history from a patient, parent, guardian, or significant other is not just a matter of asking background information but collecting data that will help you in determining the route your testing will take you.
• The information that you gather will depend on the age of the individual as well as their lifestyle and presenting symptoms.
• Always make a point of researching data and finding reliable sources

Differential Diagnosis

• Differential Diagnosis-Hearing Loss
  Autism Spectrum Disorder
  Developmental Language Disorder
  Global Developmental Delays
  Attention Deficit / Attention Deficit Hyperactivity
  Pre-existing medical condition
  Depression
  Dementia

Differential Diagnosis

• Guidance for your diagnostic path.
  Most Likely
  Less Likely
  Not Likely
  “I’m concerned the symptoms could be this…”
  “Based on the history or risk, could be this…”
  “I’ve thought about it, but I’m not concerned could be this…”

Differential Diagnosis

• Depends on an accurate historian
• Depends on the accuracy of the medical diagnosis
• Does a written diagnosis exist?
• How old is the report?
• Was testing done using American standards?
• When you put it all together, does it make sense?

Accurate Data is Key!

• Always exercise caution when a diagnosis or information is provided by a patient or parents. (Remember, their interpretation of a medical condition may not always be accurate)

Interdisciplinary Collaboration

• If significant medical history exists:
  • Get a signed release of records
  • Contact the primary care physician
  • Contact any allied health professional
  • Always get a signed release of information from the patient/client. (in some cases, this is not always easy)

Using An Evaluation Test Battery

• The more extensive testing that is completed on a patient/client, the more accurate a diagnosis will be.
  Tympanometry Otoscopy (Middle Ear Test Battery)
  Otoacoustic Emissions Audiometry (Air/Bone/Speech Testing)
  Auditory Brainstem Response (ABR) Testing Video nystagmography (Vestibular Testing)

SUMMARY

• Differential diagnosis is the process of distinguishing one disease or condition from another that may present with similar signs and symptoms.
• The process of differential diagnosis plays a significant role in what we do as audiologists and speech language pathologists.
• When applying the principles of differential diagnosis,
  the clinician is constantly gathering information which will guide the diagnostic principles. The end result will be a more
  complete plan for the patient/client.

Pure Tone Audiometry

• Sound Treated Booths
• The Audiometer
• Calibration
  • OSHA regulated (Occupational Safety and Health Administration)
  • Must be professionally calibrated on an annual basis
  • Daily biological calibration check

Basic Audiometer Components

• Frequency Selector/pure tone oscillator
• Live Microphone / Speech Audiometry
• Attenuator (typically two: one for the test ear, one for the non-test ear)
• Interrupter
• Patient response capabilities
• Output transducer
  • Headphones
  • Supra-aural
  • Knowledge Check
    • Points to review
    • Screening versus diagnostic
    • dB HL versus dB SL
    • What is 0 dBHL?
    • Outer, middle, and inner ears
    • Conductive vs sensorineural mechanisms

Pure Tone Audiometry Notes

• What is the Mastoid Process?
• Types of hearing loss
  • Conductive hearing loss
  • Sensorineural hearing loss
  • Mixed hearing loss

Air Conduction Audiometry

• Air conduction is the normal means of sound transmission in day-to-day situations.
• Pure tone air conduction audiometry determines the loudness (intensity) threshold in dB at which a person just begins to hear sound for this normal mode of sound transmission at each pitch (frequency) in Hz tested.
• determines the degree of hearing (normal or loss) at each frequency individually, for each ear individually.
• The findings cannot localize the site of damage (etiology of hearing loss). AC will give us the degree (the amount of hearing can't determine where its located
• The air-conducted signal is presented by a transducer
  • Supra aural earphones
  • Insert earphones
  • Speakers Cearphones)
• Earphone Placement
• Make sure that the headband fits appropriately.
• The center of the earphone is seated over the ear.
• Make sure Pinnas doesn't have infection/Ear can also Cears)
• Insert Earphones
• people who can't wear Standard earphones
• When are insert earphones appropriate?
• head to small for headphones
• When are insert earphones NOT appropriate?
• outer or middle ear infection
• Insert Earphone Placement
• Check placement periodically during testing

Establishing a Response Mode

• Hand-raising technique
• Patient response button
• Play audiometry techniques
• Visual reinforcement techniques
• Behavioral observation audiometry

The Hughson-Westlake Method (1944): AKA: Down 10 Up 5

• When the patient hears the tone, decrease the intensity 10 dB
• When the patient does not hear the tone, increase the intensity 5 dB
• You are seeking the lowest intensity at which the patient hears the tone more than 50% of the time. (It actually works out to be 2/3rds)
• The Hughson-Westlake Method: Threshold Search
• Order of Frequencies
• What are the “mid-octaves”?

The Audiogram: Graphing Clinical Findings

Bone Conduction Audiometry

Cochlear Stimulation through vibration

• Bypasses the middle ear (conductive hearing mechanism)
• Bone conduction results differentiate between conductive and sensorineural hearing loss (remember air conduction only establishes degree)
• Decide on placement of bone oscillator (mastoid or forehead): left or right does not matter
• Regardless of placement, the better cochlea will always respond first
• Instructions and responses are the same as air conduction testing
• Record Results on the Audiogram (Bone Conduction Audiometry)

SUMMARY

• There are basic components in every diagnostic audiometer, while screening audiometers may have less functionality.
• Supra aural earphones and insert earphones hold distinct and different clinical uses: it is up to the diagnostic audiologist to determine which is appropriate for testing.
• The Hughson-Westlake Method for pure tone threshold testing is the primary means by which results are obtained (but not the only way)

Masking

Masking-Let’s watch Keeping one ear busy while testing the other Introduction of noise into the non-test ear (NTE)

Interaural Attenuation (AI)

• Masking
  Air Conduction Bone Conduction
• 30 dB HL 30 dB HL
• 30 dB HL 30 dB HL IA = 40 IA = 0 dB dB
• 80 dB HL 40 dB HL
• 80 dB HL

Insert Earphone Interaural Attenuation

50dBHL- 60dBHL

Masking Principles

• Keeps the non-test ear “busy” while establishing results for the test ear
• Accomplished by presenting a noise stimulus to the non- test ear
• Cross-over
• Shadow curve
• Rules for masking
• What would the threshold be ↓ crossed over to the other ear not appropriately masking We get false results

Masking Rules

• When there is greater than a 10dBHL difference between the air conduction threshold of the test ear and the bone conduction threshold of the non-test ear.
• And/or when there is a greater than 40 dB difference between air conduction results between ears via supra aural earphones and 55dBHL difference when using insert earphones.
• You suspect a bilateral conductive/bilateral mixed hearing loss
• There is an asymmetry between air conduction
• There is asymmetry between the air conduction:
  *Record Results on the Audiogram

SUMMARY OF MASKING FOR PURE TONE AUDIOMETRY

• The principles of masking allow us to separate the audiometric findings between the right and left ears when there is a significant difference (asymmetry) between ears.
• Not all hearing losses are neat, pretty, and symmetrical. An asymmetrical hearing loss can be diagnosed accurately using the principles of masking.
• Interaural attenuation varies depending on the transducer used in testing:
  Bone oscillator
  Supra aural earphones
  Insert earphones
• We abide by the rules of masking when we suspect there is a difference between ears based on:
  Air conduction results of both ears
  Air conduction results of the non-test ear and bone conduction results of the test ear
  We suspect there is a middle ear pathology via other testing in our audiometric battery.
• As with all other audiometric results, masked testing results own their unique symbols on the audiogram.

Soundfield and Conditioned Play Audiometry

• Sound Field Testing
• Behavioral Observation Audiometry (BOA) Used for a child with a developmental age of up to six or seven months Responses are reflexive (eye blinks, startle responses, etc) Unlikely to be the softest sounds that a child is actually capable of hearing Testing should be viewed in conjunction with all other test results available not uncommon for multiple test sessions to be required in order for sufficient behavioral audiologic information to be obtained Visual Reinforcement Audiometry
  • Used for a child who is developmentally between (approximately) six to seven months and 24 months of age
  • Based on a child’s natural instinct to turn searchingly for an interesting sound when it’s heard
• The child will also continue to do this when “rewarded” with an appealing visual stimulus (such as lights, lighted animated toys, videos, etc.).
  Performed in the sound field using two audiologists, or with the assistance of an available Speech-Language Pathologist.
  Visual Reinforcement Audiometry
• The visual reinforcers are situated on top of each of the speakers in the sound field.
• One audiologist (or assistant) is directly facing the child and will keep the child engaged during the test process. At the same time, the other audiologist on the control side of the test suite is operating the audiometer and presenting the test sounds through the speakers.
• The child is intentionally situated between the two speakers
• The stimuli can be warbled tones, narrow bands of noise, live or recorded speech.

Visual Reinforcement (and BOA) Audiometry

Responses are recorded based on normative data

Record Results on the Audiogram

Hughson Westlake may be cast to the wind What stimulus was used?
Limitations of Soundfield Testing
Requires two sets of eyes (sometimes this means YOU!)
Developmentally is suprathreshold
Will always reveal the results of the “better ear” if an ear difference exists (Does not yield ear specific information)

Conditioned Play Audiometry

Used for a children who is developmentally (approximately) 2 ½ through 5 years of age
Makes pure tone audiometry (air and bone conduction) into a game
Can be accomplished in the Sound Field or using headphones

Record Results on the Audiogram

Pla y Testing: Standard Play
The SLP “Take-Away” for Conditioned Play Audiometry Testing
You need to know how to read an audiogram to determine if conditioned play audiometry has been performed
SLP’s must understand the cognitive level of the individual for whom play audiometry has been used (audiologist may not be present at a meeting regarding the patient/client)
The SLP should be able to examine audiological test results with a critical eye
The SLP may be employed to assist with the testing

Speech Audiometry

Speech Audiometry
What is speech audiometry?
Why do we need to do it?
How is this information used by the:
Audiologist
Speech-language pathologist

• Terminology
  Rarely agreed upon by all Varies from region to region
  Speech Audiometry Audiologist’s version of alphabet soup

A Bit of Terminology

Decibel levels (dB) threshold/level of reception versus percentage (%) clarity or discrimination of content of sound
Threshold testing is further broken into reception versus awareness

More About Terminology

SAT/SDT:
Speech awareness threshold versus Speech detection threshold (we don’t agree on this one)
SRT:
Speech recognition threshold versus speech reception threshold (this one is neat because their acronym matches)
WRT/WRS
Word recognition testing/word recognition score versus WDT/WDS word discrimination
Why do we use speech audiometry?
SPOKEN LANGUAGE IS AN AUDITORY EVENT

Test #1 Speech Reception Threshold (SRT)

What is the SRT?
Softest level (threshold) at which a patient/client can reliable repeat a word greater than 50% of the time (yes that is 2/3 by Houghson/Westlake)
Purpose of the SRT
Reliability and cross-check of pure tone findings
(Indicator of pseudohypocusis)
Reference for other speech audiometry testing
Materials used for SRT
Spondees and spondee picture boards Cold running speech
Body parts: eyes, nose, mouth, etc.
Methodology for threshold search
Familiarize patient with several words first Patient repeats the word or points to the picture
Down 10 dB, up 5 dB 2