Audiology Vocabulary

Sound Waves and Hearing

Basic Concepts

• Sound Wave: A vibration that propagates through the air and is perceived as sound.

• Pure Tone: A sound wave with only one frequency, such as that produced by a tuning fork.

• Complex Sound Wave: A sound wave containing multiple frequencies, such as speech or music.

Frequency and Intensity

• Frequency: Measured in Hertz (Hz), corresponds to the perception of pitch.

• Intensity: Measured in decibels (dB), corresponds to the perception of loudness.

Audiologic Evaluation

• Audiologic Evaluation: Comprehensive assessment of hearing function, including:

  • Case history: Gathering background information about the patient's hearing.

  • Otoscopy: Visual inspection of the ear canal and eardrum.

  • Pure-tone audiometry: Measuring hearing thresholds for different frequencies.

  • Speech audiometry: Assessing speech understanding abilities.

  • Tympanometry: Measurement of eardrum movement and middle ear function; ABR (Auditory Brainstem Response): If needed to assess the auditory pathway function.

Pure Tone Audiometry

• Pure Tone Audiometry: A hearing test that uses various tones to determine the softest sounds a person can hear at different frequencies or pitches.

Audiologic Habilitation

• Audiologic Habilitation: Therapy and support for children who are born with hearing loss to help them develop speech and language skills.

Cochlear Implants

• Cochlear Implants: Electronic devices that bypass damaged portions of the inner ear and directly stimulate the auditory nerve.

• Suitable for individuals with severe-to-profound sensorineural hearing loss who do not benefit adequately from hearing aids.

FM System

• FM System: A wireless technology that transmits a speaker's voice directly to a listener's hearing aid.

• Beneficial in noisy environments, such as classrooms.

Types of Hearing Loss

• Conductive Hearing Loss: Hearing loss due to a problem in the outer or middle ear.

• Sensorineural Hearing Loss: Hearing loss resulting from a problem in the inner ear or auditory nerve.

• Mixed Hearing Loss: Combination of conductive and sensorineural hearing loss. So problems in both the outer/middle and inner ear/nerve.

Eustachian Tube Dysfunction

• When the Eustachian tube is blocked, often due to infection, fluid can accumulate in the middle ear space.

• This fluid buildup can lead to conductive hearing loss.

Air-Bone Gap

• Air-Bone Gap: The difference between air conduction and bone conduction thresholds on an audiogram.

• Indicates the presence of a conductive component to the hearing loss, seen in conductive or mixed hearing loss.

Tympanometry

• Tympanometry: A test used to assess middle ear function.

• It measures the movement of the eardrum and can detect the presence of fluid in the middle ear.

Audiogram Interpretation

• 0 dB HL (Hearing Level): Represents average normal hearing sensitivity, not the absence of sound.

Tinnitus

• Tinnitus: The perception of ringing in the ears.

Profound Hearing Loss

• Profound Hearing Loss: Hearing thresholds worse than 91 dB HL.

Speech Discrimination

• Speech Discrimination: The ability to understand spoken words.

• In sensorineural hearing loss, speech discrimination can be impaired, causing even loud speech to sound unclear.

Anatomy of the Ear

• Eardrum: Also known as the tympanic membrane, it vibrates in response to sound waves.

• Connected to the ossicles (malleus, incus, and stapes) in the middle ear.

• Cochlea: The inner ear structure responsible for hearing; it contains fluid and hair cells.

Ossicles

• Ossicles: The smallest bones in the human body, located in the middle ear.

• Malleus (hammer), Incus (anvil), and Stapes (stirrup).

Sensory Organ for Hearing

• Cochlea: The primary sensory organ for hearing, located in the inner ear.

• Contains hair cells that transduce sound vibrations into electrical signals that are sent to the brain.

Sound Transduction

• Sound Transduction Process:

  • Outer ear collects sound waves.

  • Middle ear ossicles amplify and transmit vibrations to the inner ear.

  • Inner ear (cochlea) converts vibrations into electrical signals.

  • Electrical signals are sent to the brain for interpretation.