Hearing Loss Determining Eligibility for Social Security Benefits (2005) / Chapter Skim
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3 Assessment of the Auditory System and Its Functions
3 Assessment of the Auditory System and Its Functions
Pages 69-100
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From page 69... ...
STANDARD OTOLARYNGOLOGICAL EXAMINATION SSA regulations as presented in the Blue Book (Social Security Administration, 2003) require, as part of the disability determination process, "medical evidence about the nature and severity of an individual's impairments(s)
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From page 70... ...
SSA regulations also require that hearing tests "should be preceded by an otolaryngologic examination." In contrast, the committee recommends that the otolaryngological examination should follow the audiological examination (but by no more than 6 months) , because a physician cannot provide a competent report, including the six elements listed above, without recent audiometric data.
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From page 71... ...
During this process, the examiner can note whether the claimant does poorly under certain conditions (e.g., inability to see the examiner's face, increased distance from the examiner, presence of background noise, removal of hearing aids) and whether the claimant's behavior is consistent.
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From page 72... ...
can sometimes provide a useful crosscheck on the validity of the audiometric data. This is especially true if insert earphones are not used, because collapsing ear canals can cause apparent (but spurious)
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From page 73... ...
ASSESSMENT OF AUDITORY FUNCTION The basic audiometric test battery recommended by the committee includes assessment of pure-tone thresholds by air conduction and bone conduction, speech recognition thresholds, suprathreshold speech recognition in quiet and noise, and acoustic immittance measures.
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From page 74... ...
. The preferred earphones for air conduction threshold assessment are insert earphones to prevent ear canal collapse and ostensible high-frequency conductive hearing loss that may occur with supra-aural earphones
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From page 75... ...
Measurement of pure-tone detection thresholds is essential for determination of the degree of hearing loss, and it forms the basis of disability determination for SSA. A classification scheme for degree of hearing loss, shown in Table 3-1, is based on the mean air conduction pure-tone thresholds at 500, 1000, and 2000 Hz (PTA 512)
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From page 76... ...
This severity scale classification scheme attempts to describe the average communicative effect of a hearing loss without the use of a hearing aid. Individuals with normal hearing experience no significant difficulty hearing faint speech or speech in moderate noise levels.
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From page 77... ...
Although suprathreshold speech recognition measures are usually obtained for an auditory-only presentation mode (unisensory) , they may also be obtained for an auditory + visual presentation mode (bisensory)
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From page 78... ...
The SDT normally is obtained at a level that is 8-9 dB lower than the speech recognition threshold. The SRT is the minimum hearing level of a speech signal at which a listener correctly repeats 50 percent of the spoken message.
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From page 79... ...
Although speech recognition scores are correlated with pure-tone thresholds, the correlation is typically not high enough to accurately predict one from the other for an individual, so speech recognition must be measured directly. Most speech recognition tests are presented at levels well above the listener's detection threshold to estimate maximum potential performance.
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From page 80... ...
The reason for this lack of agreement may be related to the wider range of listening conditions sampled on selfassessment tools than in the clinical setting, the influence of emotional reactions and personality variables on individual responses to the questionnaires, or the high presentation level of traditional speech tests that does not simulate everyday listening levels. Assessment of suprathreshold speech recognition performance is relevant for SSA disability determination as an indicator of everyday speech understanding or as a potential indicator of speech understanding ability in specific listening conditions.
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From page 81... ...
First, the monosyllabic word stimuli do not represent speech used in everyday communication because they do not contain contextual cues. Second, most recorded and standardized monosyllabic speech recognition tests contain only three or four equivalent lists; this number may not be sufficient for a full evaluation.
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From page 82... ...
Sentence Tests. Speech recognition tests that incorporate the use of everyday sentences are desirable for estimating the level of performance in daily communication situations.
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From page 83... ...
Sentence recognition tests that have been developed for presentation in quiet include the CID everyday sentences (Silverman and Hirsh, 1955) and the City University of New York (CUNY)
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From page 84... ...
In addition, the S/B ratio corresponding to a 50 percent correct score can be derived. The original SIN test did not contain equivalent lists, and its level of difficulty was inadequate for listeners with normal hearing and hearing loss (Bentler, 2000)
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From page 85... ...
Thus, it is viewed as an alternate procedure to other speech recognition measures in noise. Although the HINT test was developed as a measure of SRT in quiet and in noise, the stimulus materials are often presented at a suprathreshold level to assess a percentage-correct score in quiet or in noise at fixed speech and noise levels.
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From page 86... ...
Abnormally poor performance on this test provides a diagnostic indication of the side and site of a retrocochlear lesion. Listener Performance on Speech Recognition Tests The performance of listeners with hearing loss on speech recognition tests is affected by the degree of hearing loss, the configuration of hearing loss, the site of the lesion, the listener's knowledge of the language, the
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From page 87... ...
Individual performance on a variety of speech recognition measures can be predicted with ANSI standards, including the articulation index (AI) (American National Standards Institute, 1969)
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From page 88... ...
Normative data have not been published describing validity, reliability, or performance-intensity functions in combined auditory + visual modalities for these materials. The appendix of the ANSI standard for the speech intelligibility index (American National Standards Institute, 2002b)
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From page 89... ...
For bilingual speakers, the age of second language acquisition is an important factor influencing proficiency in English. This is particularly apparent on speech recognition tests in noise: nonnative adult speakers of English who learned English before age 6 perform better in noise than adult listeners who learned the language after puberty, even though all listeners achieve nearly perfect performance in quiet (Mayo, Florentine, and Buus, 1997)
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From page 90... ...
. There are many languages for which there are no recorded versions of speech recognition tests.
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From page 91... ...
. A comparable test for assessing suprathreshold speech recognition in listeners with various linguistic backgrounds has not been developed.
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From page 92... ...
In summary, abnormal tympanograms are observed for a variety of pathological conditions affecting the tympanic membrane and middle ear, including otitis media with effusion, otosclerosis, ossicular discontinuity, tympanic membrane perforation, and a scarred (monomeric) tympanic membrane.
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From page 93... ...
Examples of conditions in which the acoustic reflex is absent include conductive hearing loss of 25 dB HL or greater in the stimulus ear, conductive hearing loss of 10 dB HL or greater in the probe ear, sensorineural hearing loss exceeding 75 dB HL in the stimulus ear, a lesion of the facial nerve in the probe ear, and a lesion in the auditory brainstem affecting the crossing pathway of the acoustic reflex arc. The acoustic reflex may also be absent with a lesion of the vestibulocochlear nerve in the stimulus ear, depending on the extent of the lesion.
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From page 94... ...
Otoacoustic emissions are produced when some of the energy from the outer hair cells is propagated through the fluids in the cochlea back to the middle ear and tympanic membrane to create a sound wave in the external ear canal (Kemp, 1986)
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From page 95... ...
The absence of an OAE alone should not be interpreted as indication of significant hearing loss. There are conditions in which the presence of an OAE alone does not ensure normal hearing sensitivity.
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From page 96... ...
This is a standard technique used to predict degree and configuration of hearing loss in infants under 6 months of age and in uncooperative toddlers. It can also be used to predict hearing thresholds in adult patients who cannot or will not respond to standard audiometric testing procedures.
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From page 97... ...
Generally, tone bursts in the frequency range between 500 and 4000 Hz provide adequate information for accurate prediction of the hearing thresholds in subjects of any age. Subjects must cooperate for the ABR evaluation by reclining and remaining nearly motionless in a darkened, sound-treated room during the test.
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From page 98... ...
. Hearing thresholds have been estimated to be within about 10-15 dB of thresholds obtained by standard audiometric techniques in adults with normal hearing and hearing loss using the multifrequency ASSR (Dimitrijevic et al., 2002)
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From page 99... ...
(Schlauch, Arnce, Olson, Sanchez, and Doyle, 1996) , absence of a "shadow" threshold curve in the poorer ear in cases of a profound unilateral hearing loss, excellent speech recognition scores at relatively low presentation levels (20 dB above admitted threshold)
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From page 100... ...
When modified procedures do not produce reliable thresholds (pure tone or speech) or suprathreshold speech recognition scores, then assessment with electrophysiological techniques such as ABR is often utilized.
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