Range of comfortable loudness (RCL): The difference, in decibels, between the threshold for speech and the point at which speech becomes uncomfortably loud. It is determined by subtracting the SRT from the UCL. Also called the dynamic range (DR) for speech.
Range of motion: The extent of movement of a joint from maximum extension to maximum flexion.
Rapidly Alternating Speech Perception (RASP): test A test for central auditory disorders in which sentences are rapidly switched from the left ear to the right ear. Normal brainstem function is required for discrimination.
Rarefaction: That portion of a sound wave where the molecules become less densely packed per unit of space.
Ratio: The mathematical result of a quantity divided by another quantity of the same kind, often expressed as a fraction.
Raw score: The number of correct answers on a test or subtest.
Reactance: The contribution to total acoustic impedance provided by mass, stiffness, and frequency.
Reactance: The contributions of mass, stiffness, and frequency to impedance.
Recruitment: A large increase in the perceived loudness of a signal produced by relatively small increases in intensity above threshold; symptomatic of some hearing losses produced by damage to the inner ear.
Rectus abdominis: Abdominal muscle that can assist with forced exhalation.
Recurrent branch: Branch of the tenth cranial nerve that innervates muscles of the larynx.
Reduplicated babbling: Long strings of consonant-vowel syllable repetitions, such as "ma-ma-ma-ma-ma."
Reference electrode: An electrode placed on an area of the scalp that is relatively unaffected by electrical activity in the brain.
Reference test gain: The acoustic gain of a hearing aid as measured in a hearing-aid test box. The gain control of the aid is set to amplify an input signal of 60 dB SPL to a level 17 dB below the OSPL90 value. The average values at 1000, 1600, and 2500 Hz determine the reference test gain.
Reflex activating stimulus (RAS): A pure tone or other acoustic signal of high intensity designed to cause the stapedial muscle to contract. The RAS can be presented through the probe assembly of an immittance meter to observe an acoustic reflex in the ear that houses the probe tip (the ipsilateral reflex), or it can be presented via an earphone in the ear opposite the probe (the contralateral acoustic reflex).
Reflexes: Automatic, involuntary motor patterns. Most disappear, but some, such as the gag reflex, remain for life.
Reinforcement: A procedure that follows a response with the intent of perpetuating or extinguishing it; used in conditioning.
Reissner's membrane: A membrane extending the entire length of the cochlea, separating the scala media from the scala vestibuli.
Reliability: In tests, the likelihood that the instrument will yield comparable results if administered by someone else, at a later date, or under different conditions.
Repetition: In fluency analysis, the process of repeating a word or a part of a word, as in "the-the-the" or "b-b-ball."
Representation: Process of having one thing stand for another, such as a piece of paper used as a blanket for a doll.
Resistance: The opposition to a force.
Resonance theory of hearing: A nineteenth-century theory of pitch perception that suggested that the cochlea consisted of a series of resonating tubes, each tuned to a specific frequency.
Resonance: The ability of a mass to vibrate at a particular frequency with a minimum application of external force.
Resonance-volley theory of hearing: A combination of the place and frequency theories of hearing, which suggests that nerve units in the auditory nerve fire in volleys, allowing pitch perception up to about 4000 Hz. Perception of pitch above 4000 Hz is determined by the point of greatest excitation on the basilar membrane.
Resonant frequency: The frequency at which a mass vibrates with the least amount of external force; the natural frequency of vibration of a mass.
Resonation: Modification of the vibratory pattern of the laryngeal tone through changes in the size and configuration of the vocal tract.
Respiratory system: The lungs, which generate the air pressure necessary for speech production.
Response: The reaction to a stimulus.
Reticular formation: Located in the brainstem, the reticular formation communicates with all areas of the brain and contains centers for inhibition and facilitation of afferent stimuli.
Retrocochlear: Located behind the cochlea.
Reverberation: A short-term echo, or the continuation of a sound in a closed area after the source has stopped vibrating. This results from reflection and refraction of sound waves.
Reverse swallow: See Tongue thrust.
Rh factor: Pertaining to the protein factor found on the surface of the red blood cells in most humans. Named for the Rhesus monkey, in which it was first observed.
Rhotic: Phonemes made with the tongue in either a bunched or turned back posture; the /r/ family of sounds.
Rhythm: Timing; stress and rate pattern of sounds or speech.
Rib cage: Twelve pairs of ribs that constitute the major portion of the thorax.
Right hemisphere injury or syndrome (RHI): A group of neuromuscular, perceptual, and/or linguistic deficits that result from damage to the right hemisphere of the brain and may include epilepsy, hemisensory impairment, and hemiparesis or hemiplegia.
Rinne test: A tuning-fork test that compares hearing by air conduction with hearing by bone conduction.
Round window: A small, round aperture containing a thin but tough membrane. The round window separates the middle ear from the inner ear.
Saccule: The smaller of the two sacs found in the membranous vestibular labyrinth; it contains an end organ of equilibrium.
Sacral vertebrae: Five fused vertebrae immediately below the lumbar vertebrae.
Sacrum: Fused structure comprised of five sacral vertebrae.
Sawtooth noise: A noise made up of a fundamental frequency of 120 Hz, with equal amplitude at all harmonic frequencies. It was found on older speech audiometers.
Scala media: The duct in the cochlea separating the scala vestibuli from the scala tympani. It is filled with endolymph and contains the organ of Corti.
Scala tympani: The duct in the cochlea below the scala media, filled with perilymph.
Scala vestibuli: The duct in the cochlea above the scala media, filled with perilymph.
Scalene muscles: Neck muscles that can assist in inhalation.
Scapula: Shoulder blade.
Schwabach test: A tuning-fork test that compares an individual's hearing by bone conduction with the hearing of an examiner (who is presumed to have normal hearing).
Schwartze sign: A red glow seen through the tympanic membrane and produced by increased vascularity of the promontory in some cases of otosclerosis.
Scintography: A computerized technique for measuring aspiration during or after a swallow.
Screening: Test for Auditory Processing Disorders (SCAN) A rapid test for central auditory processing disorders comprising three subtests: filtered words, auditory figure ground, and dichotic listening.
Search for Extraterrestrial Intelligence (SETI): The project of looking for intelligent life elsewhere in the universe.
Secondary symptoms: Idiosyncratic behaviors that are associated with stuttering, such as eye blinking and facial grimacing.
Segmental: Capable of being broken down into component parts. For example, every spoken word can be separated into phonemes.
Self-monitoring: The ability to recognize one's own errors and correct them.
Semantic features: The pieces of meaning that come together to define a particular word.
Semantic-pragmatic disorder: A mild form of pervasive developmental disorder characterized by limited vocabulary, concrete definitions, and poor conversational skills.
Semantics: The study of word and language meaning.
Semicircular canals: Three loops in the vestibular portion of the inner ear responsible for the sensation of turning.
Sensation level (SL): The number of decibels above the hearing threshold of a given subject for a given signal.
Sensitivity Prediction from the Acoustic Reflex (SPAR): Prediction of approximate degree of hearing impairment based on the level of pure tones versus a broadband noise required to elicit the acoustic reflex.
Sensitivity: The percentage of time a test correctly identifies a site of lesion.
Sensorineural hearing loss: The loss of sound sensitivity produced by abnormalities of the inner ear or nerve pathways beyond the inner ear to the brain. Formerly called perceptive loss or nerve loss.
Sensory-motor training: An approach to articulation therapy in which the client is made aware of tactile and proprioceptive sensations associated with sound production.
Serous effusion: The collection of fluid in the middle-ear space, with possible drainage into the external ear canal. Often called serous otitis media.
Serratus anterior muscle: Muscle attached to the lateral aspects of the upper ribs that can assist in inhalation.
Short increment sensitivity index (SISI): A test designed to determine a patient's ability to detect small changes (1 dB) in intensity of a pure tone presented at 20 dB SL.
Shrapnell's membrane: The pars flaccida of the tympanic membrane.
Signal-to-noise ratio (S/N): The difference, in decibels, between a signal (such as speech) and a noise presented to the same ear(s). When the speech has greater intensity than the noise, a positive sign is used; when the noise has greater intensity than the signal, a negative sign is used.
Signed exact English (SEE): A signing system for representing English that requires the breaking down of English words into syllables and representing each syllable through a specific sign.
Silent aspiration: Lack of coughing when food or liquid enters the airway.
Sinusoidal or sine waves: The waveform of a pure tone showing simple harmonic motion.
Site of lesion: The precise area in the auditory system producing symptoms of abnormal auditory function.
SLP: See Speech language pathologist.
Social worker: A professional who is sometimes the case worker for individuals with communication disorders.
Sociolinguistics: The study of influences such as cultural identity, setting, and participants on communicative variables.
Soft-voice syndrome: Compensatory behavior in which a child with velopharyngeal incompetence purposely reduces vocal intensity to prevent air escape through the nose and reduce hypernasality.
Somatogenic: Coming from the body; organic or physiological.
Somatosensory: Spatial orientation provided by proprioceptive input, as by the support the body receives on a surface.
Sone: The unit of loudness measurement. One sone equals the loudness of a 1000 Hz tone at 40 dB SPL.
Sound repetitions: Stuttering behavior where sounds are repeated, as in "p-p-p-p-pail."
Sound-level meter: A device designed for measurement of the intensity of sound waves in air. It consists of a microphone, an amplifier, a frequency weighting circuit, and a meter calibrated in decibels with a reference of 20 mPa.
Sound-pressure level (SPL): An expression of the pressure of a sound. The reference level in decibels is 20 mPa.
Spastic cerebral palsy: A congenital disorder that is characterized by increased muscle tone, such that when a muscle contracts, the opposing muscle may react abnormally to stretch by increasing muscle tone too much. Muscle movements are described as jerky, labored, and slow.
Spastic dysarthria: Speech that is characterized as slow with jerky, imprecise articulation and reduction of the rapidly alternating movements of speech because of stiff and rigid muscles.
Spastic dysphonia: A voice disorder that is characterized by hyperadduction of the vocal folds resulting in a strained/strangled voice production with intermittent stoppages.
Specific language impairment (SLI): Impairment of language that affects primarily preschoolers and cannot be attributed to deficits in hearing, oral structure and function, general intelligence, or perception; therefore, it is characterized primarily by the exclusion of other disorders. The major distinction between people with LLD and those with SLI is that those with SLI do not exhibit perceptual difficulties.
Specificity: The percentage of time a test correctly rejects an incorrect diagnosis.
Spectrum: Representation of a sound in which amplitude is displayed as a function of frequency; The sum of the components of a complex wave.
Speech audiometry: A procedure that is used to assess loudness levels at which words are understood, speech reception threshold (SRT), and speech discrimination or word identification.
Speech bulb: An obturator that fills the velopharyngeal space, closing the velopharyngeal portal.
Speech community: A group of people who share a common understanding of the rules and restrictions that govern communicative situations.
Speech conservation: Therapy to maintain clear articulation when the auditory feedback for speech production has been hindered by postlinguistic hearing loss.
Speech discrimination: or word identification test A test procedure in speech audiometry using one-syllable, phonetically balanced word lists presented at a comfortable listening level, well above threshold to examine how well a person can identify all of the individual speech sounds that give a word its meaning.
Speech fluency: The ability to move the speech production apparatus in an effortless, smooth, and rapid manner, resulting in a continuous, uninterrupted forward flow of speech.
Speech Perception in Noise (SPIN) test: A prerecorded sentence test with a voice babble recorded on the second channel of the same recording.
Speech reception threshold (SRT) or Speech-recognition threshold (SRT) test: A test procedure in speech audiometry that measures the quietest level at which a person can hear and understand speech 50% of the time using a special group of words called spondees.
Speech sample: A systematic collection and analysis of a person's speech, a corpus; used in language assessment.
Speech spectrum: The overall level and frequency composition of the energy of everyday conversational speech.
Speech: Spoken language, oral communication.
Speech-detection threshold (SDT): The hearing level at which a listener can just detect the presence of an ongoing speech signal and identify it as speech. Sometimes called the speech awareness threshold (SAT).
Speech-language pathologist (SLP): A professional whose distinguishing role is to identify, assess, treat, and prevent speech, language, communication, and swallowing disorders.
Speechreading: The use of visual (primarily facial) cues to determine the words of a speaker.
Spina bifida: A congenital malformation of the spinal column.
Spinal cord: A collection of neuron cell bodies protected within a fatty myelin sheath located within the bony spinal column.
Spinal process: Posterior projection of vertebrae.
Spiral ligament: The thickened outer portion of the periosteum of the cochlear duct, which forms a spiral band and attaches to the basilar membrane.
Spondaic word (spondee): A two-syllable word pronounced with equal stress on both syllables.
Spondee: Two-syllable compound words that are spoken with equal emphasis on both syllables and used in speech reception threshold testing. (Spondaic word)
Spontaneous otoacoustic emission (SOAE): A weak sound, emanating from the cochlea with no external stimulation, that travels through the middle ear and can be measured by a sensitive microphone placed in the external auditory canal.
Spontaneous otoacoustic emissions (SOAEs): Those sounds, produced in the cochlea, that are detectable in the external auditory canal and occur normally in persons with no hearing loss.
Spontaneous recovery: A natural recovery process that proceeds without professional intervention.
Stabilization: In the Van Riper approach to articulation therapy, reinforcement and maintenance of the corrected phoneme.
Staggered Spondaic Word (SSW) test: A test for central auditory disorders utilizing the dichotic listening task of two spondaic words so that the second syllable presented to one ear is heard simultaneously with the first syllable presented to the other ear.
Standard score: A derived score that uses an arbitrary number, such as 10 or 100, as the numerical average and uses statistical formulae to compute scores above and below this average; for example, an I.Q. score.
Stapedectomy: An operation designed to improve hearing in cases of otosclerosis by removing the affected stapes and replacing it with a prosthesis.
Stapedius muscle: A small muscle in the middle ear. Both stapedius muscles normally contract, causing a change in the resting position of the eardrum membrane, when either ear is stimulated by an intense sound.
Stapedius muscle: A tiny muscle, innervated by the facial nerve, and connected to the stapes in the middle ear by the stapedius tendon.
Stapes mobilization: An operation to improve hearing in cases of otosclerosis by breaking the stapes free of its fixation in the oval window and allowing normal vibration.
Stapes: The third and smallest bone in the ossicular chain of the middle ear, connected to the incus and standing in the oval window; so named because of its resemblance to a stirrup.
Static acoustic compliance: A measurement of the mobility of the eardrum membrane.
Stenger principle: When two tones are presented to both ears simultaneously, only the louder one is perceived.
Stenger test: A test for unilateral nonorganic hearing loss based on the Stenger principle that states, "When two tones of the same frequency are introduced simultaneously into both ears only the louder one will be perceived."
Stenosis: An abnormal narrowing, as of the external auditory canal.
Stereocilia: Small, hairlike projections on the top of each hair cell.
Sternocleidomastoid muscle: Major muscle of the neck that can assist in inhalation.
Sternothyroid muscle: Extrinsic muscle of the larynx that pulls the larynx downward.
Sternum: Breast bone.
Stiffness reactance: The quantity that results when the stiffness of a body is divided by 2pf (two times pi times frequency).
Stiffness The flexibility or pliancy of a mass. The inverse of compliance.
Stimulability: The ability to imitate a target phoneme when given focused auditory and visual cues.
Stimulus: Anything that is capable of eliciting a response.
Stoma: A small opening; for example, a surgical hole in the external neck region extending into the pharynx to permit breathing following laryngectomy.
Stopping of fricatives: The phonological process in which stop phonemes are used in place of fricatives.
Stops: Consonant phonemes produced by building air pressure behind the point of constriction.
Strain and struggle: Difficulty initiating and maintaining voice.
Strength: Power or force of muscle contraction and the accompanying amount of work a muscle can accomplish.
Stria vascularis: A vascular strip that lies along the outer wall of the scala media. It is responsible for the secretion and absorption of endolymph, it supplies oxygen and nutrients to the organ of Corti, and it affects the positive DC potential of the endolymph.
Stridor: Noisy breathing or involuntary sound that accompanies inspiration and expiration.
Stroke: Cerebrovascular accident (CVA), the most common cause of aphasia, resulting when the blood supply to the brain is blocked or when the brain is flooded with blood.
Stuttering: A disorder of speech fluency characterized by hesitations, repetitions, prolongations, tension, and avoidance behaviors.
Subglottic pressure: Pressure beneath the vocal folds that sets them into vibration.
Subluxation: An incomplete dislocation or sprain.
Substitution: In articulation, the production of one phoneme in place of another.
Sulci: Little valleys within the wrinkled cortex.
Superior longitudinal muscle (tongue): Intrinsic muscle of the tongue that elevates lateral tongue margins.
Superior olivary complex (SOC): One of the auditory relay stations in the midbrain, largely comprising units from the cochlear nuclei.
Superior temporal gyrus: The convolution of the temporal lobe believed to be the seat of language comprehension of the auditory system.
Supplemental muscles (laryngeal): Muscles that have one point of attachment on the hyoid bone and the other point of attachment on some other structure.
Support group: Individuals with similar problems who meet together to share feelings, information, and ideas.
Suppurative: Producing pus.
Supraglottic swallow: A technique in swallowing that focuses on voluntary closure of the glottis.
Supramarginal gyrus: An area in the left temporal lobe of the brain that assists in integrating visual, auditory, and tactile information and linguistic representation.
Suprasegmental: Features such as loudness, rate, and intonation that affect more than a single phoneme and add meaning to an utterance.
Suprathreshold adaptation test (STAT): A tone decay test that begins at intensities near the limit of the audiometer. If the patient hears the tone for a full 60 seconds, the test result is considered to be negative for a lesion of the auditory nerve.
Syllable final: The last phoneme in a syllable.
Syllable initial: The first phoneme in a syllable.
Syllable repetitions: Stuttering behavior in which syllables are repeated, such as "ba-ba-ba-ba-baseball."
Synapse: The area of communication between neurons where a nerve impulse passes from an axon of one neuron to the cell body or dendrite of another.
Syndactyly: Webbing of the fingers and toes.
Syndrome: A set of symptoms that appear together to indicate a specific pathological condition.
Syntax: How words are arranged in sentences.
Synthetic sentence identification (SSI): A method for determining word recognition scores by means of seven-word sentences that are grammatically correct, but meaningless.
