Central Auditory Function: Willeford Test Battery

TESTS OF CENTRAL AUDITORY FUNCTION

ALEXANDRA COSTLOW, B.S.

Willeford Low Pass Filtered Speech Test Battery

History

Developed by Jack A. Willeford, Ph.D. at Colorado State University in March of 1978.

Willeford (1977) explained that his test battery was capable of identifying subtle central auditory disorders that were not readily indicated by electro-physiologic measures (CT scan, ABR).

To date, “ … There still remains a lack of consensus of what underlies central auditory processing as well as what aspects should be evaluated by audiologists” (Medwetsky, 2009, p. 584).

History

Pre-dated by Bocca, Alearo, and Cassinari (1954) and Bocca, Calearo, Cassinari, and Migliavacca (1955) (as cited in Medwetsky, 2009). Used low-pass filtered speech stimuli to identify a

decrease in word recognition ability in the ear contralateral to the damaged hemisphere than in the ear ipsilateral to the lesion.

Subjects had normal pure tone thresholdsSuggested that pure tone and conventional

speech audiometry do not evaluate higher order auditory function.

History

Pre-dated by Bornstein, Wilson, and Cambron (1994), who used low- and high- pass filtered versions of the Northwestern University Auditory Test 6 (NU-6) for two experiments using 8 and 15 normal hearing subjects, respectively. Experiment 1: Determined word recognition ability at 70 dB HL

at four low-pass cutoff frequencies at 800, 1200, 1500, and 1700 Hz, and four high-pass cutoff frequencies at 1700,2100,2500, and 3000 Hz.

Experiment 2: Yielded psychometric functions for 1500 Hz and 2100 Hz cutoff frequencies.

Furthermore, a Binaural Fusion task can be created by simultaneously routing the 2100 Hz cutoff frequency (high-pass) to channel 1 and the 1500 Hz cutoff frequency (low pass) to channel 2.

History

Bornstein, Wilson, and Cambron (1994) found that the psychometric function for the binaural condition (slope= 4.3 dB) was essentially the same as for function for the unaltered NU-6 list (slope= 4.5 dB).

Curves for the filtered speech conditions are displaced by 8 -20 dB in comparison to the normal monaural performance.

Slopes of the filtered speech conditions are less than half (1.8 dB for the low-pass and 2.1 dB for the high-pass) than of the normal presentation.

Functions for the filtered condition reach PB max (70%) at 50 dB HL.

History

The high-pass condition is easier to understand than the low-pass condition. Performance was 11.2% higher on the high-pass condition. 35 of 40 subjects did 2-30% better on the high-pass

condition.This research met 3 goals:

Yielded equivalent word recognition scores as a function of presentation level.

Yielded maximum word recognition performance of 70%. Yielded normal word recognition scores at low

presentation levels when the high- and low-pass conditions were presented simultaneously (Bornstein, Wilson, & Cambron, 1994).

Test Development

Willeford (1977) encouraged audiologists to develop norms (especially for the Binaural Fusion and Filtered Speech Tests) for local populations due to the potential for cultural differences to affect performance.

The Binaural Fusion Test List 2 was found to be, on average, 7.8% more difficult (9.6% in a study of 30 children) than List 1; thus the 10% correction factor.

The Binaural Fusion Test presented at 40 dB SL produced a 7% increase in mean scores for a study of 40 children (ages 6-9 years); thus the 5% correction factor.

Test Development

Expanded Norms were established through data from six audiologists from four distinct pediatric populations (ages 5 – 10 years) (Willeford, 1978).

Audiometric candidacy for the study was as follows: Pure tone sensitivity not to exceed 10 dB (ANSI, 1969). Speech discrimination scores of 90% or better in either ear.

At first, children with learning disorders (LD) were excluded from the study. Public school officials urged the inclusion of these children, and they were included about half-way through the study (Willeford, 1978).

Test Development

Alternating Speech Normative Data was gathered as follows: After 25 five-year-olds had been tested and

demonstrated successful completion of this task, testing was abandoned. Apparently, even five-year-olds can complete this task relatively easily.

Children who fail this task may have behavioral needs that may indicate a personalized treatment strategy (Willeford, 1978).

Age, Gender, & Ear Effects on Performance

Riensche, Thuman, Lincoln, and Lamb (1983) found that all 4 subtests illustrated age effects. There were 94 subjects:

They were monolingual English speakers with normal pure tone thresholds and discrimination scores >90%.

They were divided into 4 groups based on age: 18-24, 60-66, 67-73, 74-80 years

Gender effects were significant on all 3 lists of the Alternating Speech Perception subtest.

Ear effects were significant on the Competing Sentences subtest.

Take-Away Message: Significant effects for age, and gender or ear, were present on all subtests and likely affected the development of normative data.

Age Effects on Performance

Kelly-Ballweber and Dobie (1984) found that there was no significant performance difference [behaviorally] between young (m=39.1 years, n=12) and old (m=69.4 years, n-12) male adults on the Binaural Fusion and Alternating Speech Perception subtests. Subjects in the young and old groups presented with some

degree of sensorineural hearing loss and were selected to audiometrically match between groups.

“No significant correlation between behavioral and electrophysiological tests” was found (Kelly-Ballweber & Dobie, 1982, p. 181).

Cassette Tape Fidelity

Shea and Raffin (1983) examined 8 original cassette tapes purchased directly from Willeford that were no more than 3 years old. Found significant differences in intensity between items within a

tape, and between tapes on all four subtests. Discrepancy of ~ 10 dB for the Alternating Speech Perception Test,

Low-Pass Filtered Speech Test, and Competing Sentences Test. Binaural Fusion Test was least uniform with as much as a 39 dB

difference between the calibrated and presented stimuli. Significant differences among tapes indicates that the use of more

than one tape per subject is not recommended. Take Home Message: Original cassette tapes were not

standardized enough to have developed reliable norms.

Cassette Tape Fidelity, In Comparison

Six cassette tapes (3 old, 3 new) were examined by the Trane Engineering and Acoustics Company of LaCrosse, Wisconsin for an independent evaluation of their fidelity.

Real-time analysis was conducted using a calibrated time-history format in reference to each tape’s calibration tone (Willeford, 1984).

Testing indicated that “ … There was no more than a 0.53 dB difference at any of the comparison data points in the sentences sampled between the three new tapes” (Willeford, 1984, p.1).

Comparison of the 3 old versus 3 new tapes revealed a mean 2.79 dB SPL difference between the 13 data points analyzed.

Pre- Testing Procedures

Cassette tapes have been replaced by compact disks (CDs).

Calibration Set the VU Meter to match the Calibration Tone at

zero in each channel. It will remain at zero for the first three tests. It may be necessary to adjust the calibration prior to

the last test, The Dichotic Sentences Test (Willeford, 1977).

Subtest Measures

Binaural Fusion subtest assesses brainstem function.

Alternating Speech Perception subtest assesses brainstem function.

Low-Pass Filtered Speech subtest assesses thalamo-cortical pathways and the auditory cortex.

Competing Sentences subtest assesses temporal lobe function (Riensche, Thuman, Lincoln, & Lamb, 1983; Shea & Raffin, 1983).

[Rapidly] Alternating Speech Perception Test

Sentences are presented in 300 ms alternating bursts

Sentences are easily repeatable by normal subjects as young as 5 years of age.

This test includes lists of 10 sentences each.Five of ten sentences per list begin in the channel

1 and the other 5 sentences begin in channel 2.Route channel 1 to one ear and channel 2 to the

other ear.The channel in which the sentence begins is

referred to as the “Lead Channel.”

Alternating Speech Perception Test

Example of test stimuli:

RE: Th f re n i r ce d n e t ee

LE: e i e g ne a d ow th s r t.

BIN: The fire engine raced down the street.

Test Instructions & Instrumentation

The subject is instructed to repeat the sentences one at a time after their presentation.

Both channels should be set to 30 dB SL re: PTA.

Record to which ears channel 1 and channel 2 are routed.

Score on the sentence as a whole: is the message accurate or not?

Record the number of sentences correct for each stimuli set.

Interpretation for Normals

Subjects from ages 5 – 75 typically perform with “perfect” accuracy.

Scoring between 90 – 100% indicates “acceptable” functioning.

Scoring may be more lenient for children< 5 years. If the meaning of the sentence is essentially correct,

then the item is deemed correct

Interpretation for an Indicated Disorder

Subjects who fail to integrate the sentence stimuli are consistently unable to perceive the message.

Inability to integrate sentence stimuli indicates a breakdown in brainstem processing. Data suggests that an inability to perform this task is

related to lesions of the caudal regions of the pontine areas of the brainstem.

This task has potential to distinguish between upper and lower brainstem disorders.

“Caudal Regions of Pontine Areas of the Brainstem”

Reliability

Willeford (1977) found little variation between ears.

There is little variation between lead channel/ear.

There is little variation between presentation of 10 items versus 20 in terms of variation between lead channels.

This is an easier task than the binaural-fusion test, likely because this task uses sentence stimuli whereas the binaural-fusion test uses word stimuli.

Channel 1 Channel 2

Low-band-pass segment (500-700 Hz) of spondaic words

Present at 30/40* dB SL re: pure tone (PT) threshold for 500 Hz to one ear.

High-band-pass segment (1900-2100 Hz) of the same spondaic words

Present at 30/40* dB SL re: PT threshold for 2000 Hz to the contralateral ear.

Binaural Fusion Test


• Familiarize the subject with stimuli from the Familiarization List prior to testing. Ex: Although, Bloodhound, Churchbell, Drugstore, Meatball,

Platform, Stairway, Wildcat

• Record ear and level (dB HL) and whether it is high or low pass.

• Instruct the subject to repeat the stimulus word.• Present monaurally to each ear, and then binaurally.• Score the ear receiving the low band.• Begin using 30 dB SL re: PT threshold.• Each correct stimuli earns a value of 5%.


Reference Binaural Fusion Norms* Chart.Retest at 40 dB SL if scores for 30 dB SL are

“Very low.” Add a 5% correction factor if testing is completed at

40 dB SL.Clinical Application: For List 2, add a

correction factor of 10% . List 2 is relatively more difficult than List 1 (as

previously mentioned in Test Development slide) (Willeford, 1978).


• Normals have difficulty with each track when presented monaurally, especially with the high band.

• However, normals are able to integrate the two bands together when presented simultaneously.o Scores progressively increase as sensation level (SL)

increases.

• Normal performance is 75% or better.• Numerous five-year-olds perform within normal

limits (Willeford, 1977).• Older adults perform normally in the absence of

processing difficulties (Willeford, 1977).


Subjects with a central auditory processing (CAP) disorder have marked difficulty on this task under all test conditions . They have difficulty with both single and binaural

presentations.The score for binaural presentation may

increase as sensation level (SL) increases above 30 dB SL re: PT threshold, but it will not reach the 75th percentile.

Alternate Test Procedure & Interpretation

Rationale: Normal subjects still do poorly when listening to an isolated band at 70 to 80 dB SL re: PT threshold. They will still score below the 75th percentile. If this condition is satisfied, the bands may be

presented at a level below the ceiling for a single- band presentation for testing (Willeford, 1977,).

Filtered-Speech Test

Uses degraded or frequency-distorted speech.Stimulus words were selected from a list of

Michigan CNC words.CNC words are passed through an electronic

filter. Filter Characteristics:

Low-pass cutoff: 500 Hz Rejection characteristic: 18 dB per octave for frequencies

above 500 Hz

The selected CNC words are still highly intelligible to normal adult subjects. Sample Words: Hide, Home, Lap, More, Root


Present List 1 to one ear and List 2 to the other ear, monaurally. Test Level: 50 dB SL re: Pure Tone Average (PTA)

Record test ear on the form.Instruct the subject to repeat each word after

its presentation.Caution the subject that the words are

supposed to be difficult to understand.Encourage the subject to use their best guess

if they are not sure of what they heard.


70 – 100% is a normal score for subjects ages 10 – 60 years.

Scoring for children under 10 years of age shows bilateral maturation effect (Willeford, 1977). Refer to Filtered Speech Norms Table to interpret

scores for children ages 5 – 10 years.


Abnormal results are indicated when the bilateral score is <70%.

Abnormal results are indicated when there is >10% asymmetrical performance between ears with poorer performance in the ear contralateral to the cortical lesion.

Surgical investigation on adults with such results indicated temporal lobe damage. Temporal lobe damage is more diffuse and deep

(Willeford, 1977).

Temporal Lobe Auditory Cortex

Surgical Confirmation

Filtered Speech and Dichotic Test Findings

Results between these two tests may be confounded with deep parietal lobe lesions.

Filtered Speech Test Performance

Dichotic Test Performance

May be normal.May be abnormally

low in both ears.

These lesions produce abnormal performance in the ear ipsilateral to the language-dominant hemisphere.

Filtered Speech vs. Dichotic Test Findings

Dichotic SentencesCompeting Sentence Test/Unilateral Response

(CST/UR)

There is a primary message (sentence) and a competing message (sentence).

Present the primary message to one ear and the competing message to the contralateral ear.

Reverse the procedure by playing the other list as the primary message to the other ear. Subjects who are instructed not to repeat the

competing message do not remember the competing message, so the competing message can be used as the primary message in the opposite ear (Willeford, 1978).


The primary message channel is set to 35 dB SL re: PTA.

The competing message channel is set to 50 dB SL re: PTA.

Thus, the signal to noise ratio (SNR) is -15 dB.Ex:

Primary Ear (Right): Leave the keys in the car (35 dB SL) Competing Ear (Left) : Fill the tank with gas (50 dB SL)

Instruct the subject to repeat the sentence presented to the right ear and to ignore the sentence presented to the left ear.

Record the Test and Competing ear dB HL.


Adults subjects should be able to perform this task with little difficulty.

Children usually score 100% in one ear, and may score from 0- 100% in the weaker ear. A score of 0% is the most common score for children

ages 5 and 6 (Willeford, 1978). Performance of the weak ear progressively improves

until age nine (Willeford, 1978).o A disorder is indicated when the better ear’s

performance is <90% or when the weaker ear does not improve to equal the better ear’s performance at age 9.

Interpretation for Indicated Disorder

Subjects with temporal lobe lesions perform poorly in the ear that is contralateral to the damaged lobe. Especially when the lesion is located posteriorly. Anterior lesions seem not to affect performance (Willeford, 1978).

Adults with deep parietal lobe lesions generally show decreased performance in the left ear (Willeford, 1978).

Children with learning disabilities (LD) may show reduced performance in one (usually the left) or (occasionally) both ears (Willeford, 1978).

According to Matkin (1979) and Pinhiero (1978) in Willeford (1979, p. 5), this is an effective test to use with children with learning disorders.

Reliability

Only 10 sentences are necessary to confirm cortical lesions in adults.

Thus, one list can be used to test each ear, and the 5 remaining sentences can be ignored (Willeford, 1978).

Competing Sentences Test (BR)

Memory Effects One might think that the subject’s ability to remember two

sentences may affect CST (BR) performance. However, when subjects were unable to repeat back sentences

on the UR task, it was because of the competing message, and not because of memory demands. Subjects generally miss items in only one (versus two ears). Subjects generally do not have difficulty when presented with stimuli

without competition.

Subjects who are unable to perform this task are usually able to perform the Alternating Speech Test, which employs sentences that are as complex and perhaps longer than those on the CST (BR) (Willeford, 1979).

Competing Sentences Test (BR) Development

Subjects included 120 children (50 males, 70 females) who were 6 – 12 years of age from (Mesa, AZ) Arizona Public Schools. Subjects were from varying levels of socioeconomic

status. Subjects with learning disabilities were excluded. Subjects with a PT Threshold >15 dB HL at any

frequency were excluded.Subjects were presented with test items 21-

25 for practice.


Test List Equivalency testing was conducted as follows: 15 subjects were presented with items 1- 10 first, and

items 11- 20 second. 15 subjects were presented with items 11-20 first, and

items 1 -10 second. Mean scores and range of scores were

comparable between lists (Willeford, 1979).The BR task is a considerably more difficult

task than the UR task, despite a more intense presentation level/SNR (Willeford, 1979).


Age Norms were gathered as follows: For 6 year-olds, this task proved very difficult, and

testing for 6 year-olds was abandoned. Testing then focused on children aged 8 – 12 years. Testing of 6 year-olds was re-investigated as a matter

of curiosity. There was not enough time to test the 7 year-olds, so

scores for that age range were interpolated (Willeford, 1979).

Competing Sentences Test/Bilateral Response (CST/BR)

Alternate CST that tests ability to repeat both the primary and competing sentences when presented bilaterally.

Normal subjects can complete this task (Willeford, 1977).

Deliver the stimulus at 50 dB SL re: PTA to both ears. Yields a SNR of 0 dB.

Each correct item is worth 10% of the total score.Score this task liberally with children.

An item is incorrect when the message can not be repeated or it loses its intended meaning (Willeford, 1978).

Each sentence correct (per one ear) is worth 5%.

In Review…

Alternating Speech Perception subtest: Tests binaural integration of stimuli (sentences).

Binaural Fusion subtest: Tests binaural fusion of high-frequency and low-frequency stimuli (spondees).

Filtered Speech subtest: Tests monaural discrimination of low-pass-filtered degraded stimuli (CNC words).

Dichotic Sentences Competing Sentence subtest - Unilateral: Tests ability to attend to desired stimuli (sentence) in the presence of competing message.

Dichotic Sentences Competing Sentence subtest – Bilateral: Tests ability to attend to 2 desired stimuli (sentences) simultaneously.

Validity of the WLPFSTB

Musiek, Geurkink, and Kietel (1982) administered 7 tests, including the 4 WLPFSTB subtests, to 22 children (ages 8 – 10 years). Determined that the Low-Pass Filtered Speech subtest

(LPFS) and the Rapid Alternating Speech subtest (RASP) were less effective in distinguishing children with auditory perceptual dysfunction from normal subjects than other tests.

Determined that the Competing Sentences subtest was a superior detector than the LPFS and RASP subtests.

The Binaural Fusion (BF) subtest was administered at 50 dB SL, compared to the normal 30 dB SL. At 50 dB SL, the BF subtest was less sensitive at detecting perceptual dysfunction than other tests.

Validity of the WLPFSTB Cont.’d

Musiek, Geurkink, and Kietel (1982) further noted that a test battery approach was favorable to detecting auditory perceptual dysfunction than any one test. As the number of tests increased, the sensitivity of the

battery increased. However, a test battery of Competing Sentences and

Frequency Patterns (not a WLPFSTB subtest) is as effective at detecting failures as the 7 test battery.

Take Home Message: A test battery approach is favorable to one test, but only one (arguably 2, including the BF subtest) WLPFSTB subtest/s effectively identifies abnormal subjects.

Validity of the WLPFSTB A Different Perspective

Singer, Hurley, and Preece (1998) tested 91 children with normal learning ability and 147 children with a learning disorder and presumed CAPD (ages 7 – 13). Of the 7 tests given, the Binaural Fusion and Filtered

Speech subtests were most effective in identifying normal versus abnormal subjects.

A test protocol of the Binaural Fusion and Filtered Speech subtests was most effective considering hit rate, false + rate, and cost.

However, the Binaural Fusion and the Masking Level Difference tests together best identify abnormal performance.

References

Bornstein, S. P., Wilson, R. H., & Cambron, N. K. (1994). Low- and high- pass filtered Northwestern University Auditory Test No. 6 for monaural and binaural evaluation. Journal of the American Academy of Audiology, 5, 259-264

Kelly-Ballweber, D., & Dobie, R. A. (1984). Binaural interaction measured behaviorally and electrophysiologically in young and old adults. International Journal of Audiology, 23(2), 181-194.

Medwetsky, L. (2009). Mechanisms underlying central auditory processing. In J. Katz, L. Medwetsky, R. Burkard, L. Hood (Eds.) Handbook of clinical

audiology (pp. 584-641). Philadelphia, PA: Lippincott, Williams & Wilkins. Musiek, F. E., Geurkink, N. A., & Kietel, M. A. (1982). Test battery assessment

of auditory perceptual dysfunction in children. The Laryngoscope, 92(3), 251-257.

Parietal lobe [Illustration]. Retrieved April 20, 2010, from http://www.cnn.com/fyi/ interactive/news/11/brain/parietal.jpg

Riensche, L. L., Thuman, P. R., Lincoln, K. L., & Lamb, L. E. (1983). Age effects on performance on the Willeford Central Auditory Test Battery. Journal of Auditory Research, 23(2), 131-135.

http://www.cnn.com/fyi/

References Cont.’d

Singer, J., Hurley, R. M., & Preece, J. P. (1998). Effectiveness of central auditory processing tests with children. American Journal of

Audiology, 7, 73-84. Shea, S. L., & Raffin, M. J. M. (1983). Assessment of electromagnetic

characteristics of the Willeford Central Auditory Processing Test Battery. Journal of Speech and Hearing Research, 26, 18-21.

Willeford, J. A. (1977). Procedures for Tests of Auditory Function. Retrieved from The University of Maryland ELMS Blackboard Site.

Willeford, J. A. (1978). Expanded Central Auditory Test Battery Norms. Retrieved from The University of Maryland ELMS Blackboard

Site. Willeford, J. A. (1979). Bilateral – Response (CST/BR) Norms. Retrieved

from The University of Maryland ELMS Blackboard Site. Willeford, J. A. (1984). Acoustic Consistency of the Willeford Central

Auditory Test Tapes. Retrieved from The University of Maryland ELMS Blackboard Site.

References Cont.’d

[Untitled image of the lobes of the human brain]. Retrieved April 20, 2010, from:

http://www.dwp.gov.uk/img/brain.gif[Untitled Microsoft Illustration of the brainstem].

Retrieved April 20, 2010, from:

http://people.eku.edu/ritchisong/RITCHISO/301notes2b.html

Zatorre, R. J. (Physician and Photographer) (2005). Untitled [Functional Magnetic Resonance

Image], Retrieved April 20, 2010, from: http://www.dana.org/news/brainwork/detail.aspx?

id=766

http://www.dwp.gov.uk/img/brain.gif



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Central Auditory Function: Willeford Test Battery