Hearing Science Test 4
Terms
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- The threshold of audibility. It is the point at which the minimum sound pressure level (in dB) may first be perceived
- absolute threshold
- The normal route of hearing. Sound first enters the external ear canal, passes across the middle ear as vibration, and then travels to the inner ear. When an earphone is used to deliver sounds during an audiological examination, the sound is said to be d
- air conduction
- refers to a relatively recent standardization of the sound pressure levels that represent normal hearing for pure tones and speech. (1969) extablished normal hearing frequency
- ANSI (American National Standards Institute, Specification for Audiometers
- a mechanical device on which an earphone is placed. Its purpose is to approximate the sound pressure levels produced by a sound at the tympanic membrane. It consists of a coupler that is mechanically attached to the microphone of a sound level meter. The
- artificial ear
- a graph that shows hearing loss ( in dB) as a function of stimulus frequency
- audiogram
- the method by which hearing sensitivity is measures; pure tones and speech tones are the most typcial signals used in this
- audiometry
- an automated type of audiometry in which the subject tracks his own thresholds; examinee controls the hearing level
- Bekesy hearing
- refers to hearing with two ears
- binaural hearing
- occurs when sound passes to the inner ear through the cranial bones. During an audiological examination, a special _________ vibrator is used to test for _____________ sensitivity. The usual placement is on the mastoid process.
- bone conduction
- the difference between the subject's threshold for that sound and the corresponding normal threshold. The intensity dial of an audiometer is calibrated in this (in dB)
- hearing level
- one of the three classical psycholphysical methods. In this method, the subject adjusts some aspect of the stimulus to meet some criterion set by the experimenter
- method of adjustment
- One of the three classical psychophysical methods. In this method the various "constant" stimuli are presented randomly to the subject. The subjects task is to make some judgment about each stimulus presentation. For example, in an experiment d
- method of constant stimuli
- One of the three classical psycholophysical methods. In this method, the stimuli are adjusted by the experimenter in alternating ascending and descending series. The subject's task si to make some judgment about each of the stimuli. For example, a judgme
- method of limits
- a method of measuring hearing sensitivity. It is the sound pressure level (in dB) of a tone at the threshold of audibility. It is measured in a free sound field at the place occupied by the subjects head, after the subject has been removed from the room.
- minimum audible field (MAF)
- a method of measuring hearing sensitivity. It is the sound pressure level (in dB) of a tone at the threshold of audibility. It is obtained using an earphone, adn then measuring or inferring the sound pressure level at the tympanic membrane
- minimum audible pressure (MAP)
- refers to hearing with one ear only
- monaural hearing
- the range of sensitivity found when a group of otologically normal individuals is tested. The individuals in the test group should not have been exposed to prolonged periods of noise. The ages of individuals, as well as the method of threshold measuremen
- normal hearing
- an interval between two frequencies with a ratio of 2:1
- octave
- a gerneral term that refers to the diminuation of hearing sensitivity with advancing age
- presbycusis
- the relationship between stimulus duration and the threshold of audibility. Within specified limits, the shorter a stimulus, the more energy will be required to reach the audible threshold
- temporal integration
- room which contains huge wedges of fiberglass; produces an absense of sound; designed to stop the reflex of sound
- anechoic chamber
- a routine part of an audiometric examination. a small device known as a bone conduction vibrator is held against the patient's mastoid process by a metal band. Sound vibration is then delivered directly to the inner ear through the bone conduction route,
- clinical bone conduction
- operative at high frequencies. It is thought that the skull itself is alternatively compressed and expanded by the sound vibration. As this compression and expansion occurs, it causes the oval and round windows to expand and contract. This occurs because
- compression bone conduction
- a situation in which the acoustic stimuli presented the ears differ. The sounds may differ in terms of their frequencies, intensities, phases, durations, etc
- dichotic listening
- a situation in which both ears receive indentical sounds at the same instant in time
- diotic listening
- operative at low frequencies; the skull is thought to vibrate as one body. THe stapes, however, is not rigidly attached to the temporal bone at the oval window. When the skull vibrates, both the skull and stapes wil move. However, the stapes will tend to
- inertial bone conduction
- one of the cues that facilitates auditory localization. This difference between the ears is primarily found for high-frequency tones. At these frequencies the head serves to reduce the sound reaching the ear opposite the sound source. For this reason, th
- interaural intensity difference
- one of the cues that facilitates auditory localization. The time differenc ebetween the ears arises because the ears are separated by about 11 inches, on the average. The effect of interaural time difference on localization ability is greatest for low fr
- interaural time difference
- refers to the location, within the head of an auditory signal presented over earphones. For example, the image may appear to come from either ear, the midline, or some position between the midline and either ear
- lateralization
- refers to a situation in which a listener localizes sound in space. The listener may localize direction, or distance, or both.
- localization
- the contribution to bone conduction hearing which occurs when the vibrating skull causes the air in the external auditory meatus to vibrate
- osseotympanic bone conduction
- equal to the number of decibels that a given sound is above the threshold of audibility for a given individual
- sensation level (dB SL)
- the process by which an ear not under test in an audiometric examination is masked to eliminate the possiblity of cross-hearing
- clinical masking
- a hypothetical band of frequencies that surrounds a test frequency in the masking process. When a pure tone is masked by noise, it is suggested that only those noise frequencies that fall within the critical band will be effective in the masking process.
- critical band
- the phenomenon in which the nontest ear in an audiometric examination receives the audiometric signals and the subject responds. Cross-hearing, of course, may lead to erroneous conclusions. To eliminate cross-hearing, masking noise is applied to the nont
- cross-hearing
- equal to the number of decibels that a masker shifts the threshold of the test stimulus, usually a tone. For example, a masking noise that is 15dB effective will shift threshold 15 dB. The 0 dB effective masking point occurs at the level of the masker wh
- effective masking level
- the insulation provided by the head between the two ears. Clinically speaking, this provided by the head for air-conducted sound is about 40 dB, and for bone-conducted sound is 0 dB. That is, the head provides about 40 dB of isolation between the ears fo
- interaural attenuation (IA)
- the threshold of a sound obtained in the presence of a masker; is uaually expressed in sound pressure level in decibels.
- masked threshold
- refers to the number of decibels that the threshold of one sound is raised by the presence of another sound
- masking
- the masking effect of a masker. It is measured in decibels, and it is numerically equal to the difference between the stimulus threshold in quiet, and the threshold with the masker present
- threshold shift
- a clinical procedure by which the phenomenon of loudness recruitment is demonstrated
- alternate binaural loudness balance (ABLB) test
- a curve that relates equal loudness sensation (in dB SPL) for various frequency counds. The referency frequency against which the loudness of all other frequencies is compared is 1000 Hz
- equal-loudness contour
- the aspect of sound perception in which sounds may be ordered form "soft" to "loud." Its perception is principally related to stimulus intensity, but frequency also plays a role
- loudness
- a phenomenon very often associated with cochlear heraing loss. When this occurs, loudness sensation increases more rapidly than normal at levels just above threshold. However, at higher levels the sensation of loudness becomes normal
- loudness recruitment
- a psycholphysical salce of pitch perception. The unit of this it the mel. ONe thousand are equivalent to a 1000-Hz tone set at a sound pressure level of 40 dB
- mel scale
- a unit of loudness. The number of _____ for any frequency tone is equal to the sound pressure level (in dB) of a 1000-Hz tone judged to be equally loud
- phon
- the psychological perception of frequency. It is that aspect of a sound which can be ordered from "high" to "low." It is primarily related to frequency in such as way that low frequency sounds produce low ______, and high frequencies
- pitch
- a function that realtes subjective perceptions to physical events. That is , these scales seek to quantify the relationships between physical and psychological events. Both the sone and mel scales are examples of this
- psychophysical scale
- a psychophyscial saling method in which the subject is required to produce a prescribed ratio between two stimuli. The ratios most often set by the the subjects are either 2:1 or 1:2
- ratio production
- abnormal growth of loudness
- recruitment
- an arbitrary unit of loudness. It is defined as the loudness of a 1000-Hz tone set at 40 dB above threshold (40 dB sensation level)
- sone
- a ratio scale of loudness in which the arbitrary unit of loudness is the sone
- sone scale
- in many psychophysical experiments two signals are presented to the subject for comparison. The first is usually the standard and the second, the comparison. The subject is then asked to make some judgment of the comparison relative to the standard. For
- standard stimulus