Comprehensive Study Notes on Audiology and Hearing Science

Audiology and Speech Pathology

  • The instructor may adjust the course schedule to cover tympanograms, OAE (Otoacoustic Emissions), and ABR (Auditory Brainstem Response) depending on the progress and understanding of pure tone and speech testing.
  • Students likely won't perform these tests as clinicians but should understand them to explain reports to parents in child study team meetings.
  • The course aims to provide a comprehensive understanding of audiology relevant to various settings, including hospital, adult rehab, and pediatrics.

Career Settings

  • Adult Rehab: May involve aural rehab or troubleshooting hearing aids, especially in facilities without a dedicated audiologist.
  • Hospital Setting: Varies in audiology department availability.
  • Course aims to provide a foundational understanding of audiology applicable across different work environments.

Student Background

  • Students have completed their first year and are either attending classes two days a week or have finished spring clinic.
  • Remaining coursework is a mix of in-person and Zoom sessions.

Course Logistics

  • The instructor plans to schedule a final exam, possibly on a Thursday morning or afternoon, due to a personal commitment.

Instructor's Background

  • Undergraduate degree from Stockton, Master's in Audiology from Temple University.
  • Dual certification in speech pathology; doctorate obtained later in career when audiology was transitioning to a doctoral level.
  • Experience includes working in rehab, the VA hospital in Philadelphia, and schools.
  • Currently works as an educational audiology consultant for special services, covering multiple schools due to the lack of mandated educational audiologists in New Jersey.

Course Introduction

  • The initial topics will cover the history of audiology, acoustics, and hearing science, which may not be the most exciting but are foundational.
  • Content may overlap with speech and hearing science courses.

Quizzes and Textbook

  • Instructor will indicate key concepts to know for quizzes.
  • Quizzes will be in pen-and-paper format, with a mix of multiple-choice and fill-in-the-blank questions (approximately 20 questions).
  • An extra textbook is available for students to share.
  • Slides combine publisher content with the instructor's previous materials.

What is an Audiologist?

  • Audiology is the study of hearing.
  • In clinical settings, audiologists perform tests, see patients, and fit hearing aids.
  • In schools, audiologists focus on fitting hearing aids to classroom needs.
  • Counseling and patient interaction are crucial aspects of the job.

History of Audiology

  • Speech pathology is an older profession than audiology.
  • Audiology emerged from military hospitals after World War II due to veterans with significant hearing loss; initially, duties were performed by physicians or speech pathologists.
  • The field developed in the 1950s-1970s.
  • Audiologists were not always allowed to dispense hearing aids, a change that significantly impacted the profession.

Becoming an Audiologist

  • Requires completing a master's degree plus a nine-month clinical fellowship.
  • The field transitioned to a doctoral (AuD) level, with a transition program for experienced professionals.
  • The first professional doctorate (AuD) was introduced in 1996.

Licensing and Certification

  • A state license is required to practice audiology in all 50 states.
  • ASHA (American Speech-Language-Hearing Association) is a primary national certification organization, but many audiologists now prefer AAA (Academy of Audiology) due to its focus on medical audiology.
  • ASHA certification requires ongoing fees.
  • Certification is not mandatory everywhere but is professionally valuable.

Prevalence of Hearing Loss

  • More than 5% of the world's population has debilitating hearing loss.
  • Examples of students with hearing loss are shared, highlighting varying experiences and challenges.

Specific cases of hearing loss

  • A 22-year-old student has hearing loss in both ears but doesn't use hearing aids.
  • Another student has permanent damage to their left ear due to a burst eardrum.
  • Another student previously had ear tubes inserted multiple times due to a hole in her left eardrum

Personal Experiences with Hearing Loss

  • The instructor shares personal experiences with medication-induced (ototoxic) hearing loss, tinnitus, and hyperacusis.
  • COVID-19 booster shots exacerbated tinnitus in some individuals with pre-existing hearing issues.

Impact of Ototoxic Medications

  • Ototoxicity is discussed in the context of medication side effects (e.g., some meningitis treatments).

Prevalence in Different Age Groups

  • 14 million baby boomers are at risk for age-related hearing loss.
  • 7 million school-aged children have some degree of hearing loss.
  • Gen X and younger generations (Gen Z, millennials) are experiencing increased hearing loss due to noise exposure from music and headphones.

Impact on Children

  • Critical language development window is between three to five years old; chronic ear infections during this period can have significant impact.
  • Cochlear implantation is done at younger ages now, with some children implanted as early as one year old.
  • Outcomes vary based on follow-through and support; some children with early intervention achieve language skills on par with hearing peers, while others may struggle.
  • Severe permanent hearing loss significantly impacts speech and language development.

Audiologist's Role

  • Audiologists are healthcare professionals providing patient-centered care, prevention, identification, and diagnosis of hearing and balance disorders for all ages.
  • Prevention includes hearing conservation programs and screenings.
  • Early hearing screenings are crucial for children, especially before speech therapy.
  • Important to know hearing status before certain types of testing like speech therapy.
  • Hearing screenings should be done for children referred to child study teams.
  • Hearing and vision screenings should be conducted through the nurse.

Scope of Practice

  • Includes hearing screens, evaluations, CAPD (central auditory processing disorder) evaluations, electrophysiologic testing (otoacoustic emissions, ABRs), and advanced treatment.
  • Auditory training may fall under speech pathology.
  • Works as part of an interdisciplinary team.

Work Settings

  • Varied, including medical settings, educational institutions, pediatric centers, and private practices.
  • Dispensing audiologists primarily focus on fitting hearing aids.
  • Industrial audiology involves hearing conservation programs in workplaces.
  • Specializations include vestibular testing and cochlear implant audiology.

Professional Associations

  • ASHA and AAA are primary associations; specialty associations like the Educational Audiology Association provide additional resources and peer feedback.

Interprofessional Collaboration

  • Collaboration with other professionals (e.g., psychologists, OTs) is essential, especially in cochlear implant teams, cleft palate teams, and for auditory processing evaluations.

Job Outlook

  • The job outlook for audiologists is positive.

Role of Speech Pathologists

  • Speech pathologists provide aspects of aural rehab and basic hearing aid checks.
  • In schools, speech pathologists may conduct daily listening checks for students with hearing aids.

Questions and Discussion

  • The instructor concludes the session and opens the floor for questions, addressing student concerns about the quiz format and content.

Introduction to Acoustics

  • Acoustics and sound measurement will be explored, including physical and psychological aspects.

Sound Generation and Transmission

  • Sound is generated by molecule movement/vibrations through solids, gasses, or liquids.

Physical vs. Psychological Terms

  • Physical: Frequency and intensity.
  • Psychological (Psychoacoustics): Pitch (high/low), loudness, related to perception.

Sound Characteristics

  • Vibrations: Occur in the ear.
  • Elasticity: How springy an object is (e.g., middle ear system).
  • Sound travels through the air in the form of waves.

Compression and Rarefaction

  • Rarefaction: Particles are further apart.
  • Compression: Particles are closest together (peak).

Types of Waves

  • Transverse
  • Longitudinal
  • Sinusoidal

Key Wave Concepts

  • Frequency: Cycles per second; determines pitch.
  • Longitudinal Waves: Particles vibrate parallel to the direction of wave energy.
  • Transverse Waves: Particle movement is perpendicular to the wave's movement.
  • Sine Wave: Mathematical/graphical representation of a longitudinal wave.

Pure Tones

  • Rare in the environment; used for testing.
  • Tuning forks produce specific frequencies and can be used for bone conduction testing.

Audio Spectrum

  • Range of frequencies humans can hear.
  • Molecules move faster in higher pitches.

Measurement and SPL

  • Sound Pressure Level (SPL): Measures ambient noise or is used in research.
  • The average person's hearing threshold is used to determine audibility.

Wave Properties

  • Frequency of a wave - cycle per second
  • In a lower pitch, the molecules are more spread out and are moving slower. In higher pitches, the particles are faster, closer together, also being more ten year.

Impact of Mass and Stiffness on Frequency

  • As mass increases, the frequency decreases (e.g., thicker guitar strings).
  • As stiffness increases, the frequency increases (e.g., tight wire).

Amplitude and Intensity

  • Amplitude indicates the intensity of the sound (measured in decibels).
  • Higher amplitude = louder sound.

Complex Tones

  • Multiple tones combined (e.g., speech, music).
  • Can be periodic (patterned) or aperiodic (random).

Impedance

  • Opposition to energy flow; increases with density.
  • Relevant in tympanometry, which measures eardrum movement in response to pressure changes.
  • Flat tympanogram indicates fluid in the middle ear, preventing eardrum movement.

Decibel (dB) Measurement

  • Various dB scales: DBSPL, DBHL, etc.
  • DBHL: Common for audiograms.
  • DBSPL: Sound pressure level, used for ambient noise measurement and research.
  • DBHL is calculated based on SPL averages from 18-25 year olds.
  • Sensation level is used in speech testing; calculated as presentation level above the person's threshold (presentation level + threshold).
  • Audiometers are calibrated with DBHL.
  • DBHL zero does not mean the absence of sound, but it is below what the average person can detect, this is also why it goes below zero sometimes.
  • Loudness grows faster in low frequencies and certain high frequencies than it does in the main frequencies.

Sound Level Meters

  • Measure sound pressure levels in different environments.
  • A-weighted measurements are commonly used; C-weighted are used more in industry.
  • Prolonged exposure to high dB levels can be harmful.

Testing Environment

  • Quiet testing environments are essential for accurate results.

Introduction to Psychoacoustics

  • Psychoacoustics is the psychological response to sound (pitch, loudness, localization, masking).

Key Concepts

  • Pitch: Related to frequency. Higher frequency = higher pitch.
  • Loudness: Related to intensity.
  • Localization: Ability to determine the source of a sound.
  • Requires two ears at equal hearing level
  • Masking: When one sound covers another; relevant in special testing.

Localization

  • Important with kids in the classroom. If a child has a nonfunctioning ear, then he/she could miss things due to noise.

Diagnostic Audiometer

  • Can perform air, bone, speech testing
  • The diagnostic audiometer can perform different types of speech testing (live voice or recorded)

Transducers

  • Devices for presenting sound (headphones, earphones, bone conduction vibrators).
  • Sound field testing is used with young children, where the sound comes from different sources.

Types of audiometers

  • Portable
  • Clinic
  • Screeners

Sound Level meter

  • Should be performed for at least 8 hours
  • Used to determine levels in a room or area for testing.
  • Salon lasers are used to calibrate

Weighting

  • A weighting (mostly used)
  • C weighting (Industry)
Room Levels

If one suspects that a patient has hearing loss and you want to test them, think about the testing environment. You will need:

  • A quiet room
  • Proper weighted/calibrated testing equipment