Long term auditory response · automatic and once initiated continues until the baby'passes' or'fails'. ('Failure' is usedin thispaper to identify those babieswhodonotachievethe97%

Archives of Disease in Childhood, 1984, 59, 504-511

Original articles

Long term follow up of newborns tested with theauditory response cradleJ BHATTACHARYA, M J BENNETF, AND S M TUCKER

Brunel University and Hillingdon Hospital, Uxbridge, Middlesex

SUMMARY The auditory response cradle is being used in a mass hearing screening project. Babiesare assessed in the first week after birth by the fully automatic, microprocessor controlled cradle.The test, lasting from two to 10 minutes, compares physiological auditory responses to naturalbehaviour measured in control trials. More than 5000 babies have been tested and full follow up

information at the age of 7 to 9 months is available from over two thirds of these. Less detailedinformation is available for 71% and 64% of those babies who have been followed up at 18months and three years of age respectively.A total of 439 of 5553 neonates tested failed the first screening test. Eighty eight (1-6%) failed

a second screening test while still in the maternity unit but 61 of these were subsequently shownto be normal, giving a false positive rate of 1-1%. The babies who failed the screening testsincluded 9 with sensorineural hearing loss, three with secretory otitis media, and three withabnormal auditory brain stem response tests. One child who passed the initial screening tests wasfound to have a moderately severe hearing loss at the age of 18 months.

The importance of the early detection of hearingimpairment has been stressed by all those dealingwith the deaf.' 2 An intact auditory pathway isessential for the acquisition of speech and languageand as the critical time for the development of theseskills is during the first two years of life, earlydiagnosis is highly desirable.3 The earlier the hear-ing loss is identified the sooner appropriate manage-ment can be instituted that will allow the child toachieve his full potential.4

In an attempt to achieve early diagnosis a 'highrisk' register has been widely used but only approxi-mately 50% of hearing impaired babies are on sucha list.5 6 More centres have recently begun to useauditory evoked potentials, in particular brainstemresponses, for the differential diagnosis of hearingimpairment.7 These procedures, however, are timeconsuming, require expensive equipment, and needskilled personnel for interpretation,8 all of whichtend to negate their use for mass screening.

Traditional techniques for the assessment ofhearing in children aged up to 2 years have centredaround the observation of behavioural responses tosound. Below the age of 6 to 7 months this isexceptionally difficult. Although child development

patterns are well documented, observer bias, lack oftesting standardisation, and inexperience affect thereliability of response detection and classification.In neonates the situation is little better as there isneed to distinguish spontaneous activity from speci-fic responses to sound; strict conformity with arbi-trary criteria has resulted in high false positive andnegative rates.9-11The auditory response cradle was developed to

classify neonatal responses to sound accurately.These responses were measured and subjected tostatistical analysis in extensive research trials'2 13and the automatic, microprocessor controlled audi-tory response cradle was designed from the resultsobtained. The auditory response cradle consists of atrolley mounted unit comprising a pressure sensitivemattress and head rest (Figure). These incorporatenon-contacting sensors for head turn, startle or headjerk,'4 16 body activity, and respiration.13 i5 A 2600Hz high pass noise of 85 dB SPL is used as the teststimulus and is presented via close coupled earprobes fitted with tips similar to those used foracoustic impedance testing. High pass noise is usedbecause of the prevalence of high frequency impair-ment among the congenitally deaf. The sound

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Long term follow up of newborns tested with the auditory response cradle 505

Figure A baby being tested in theauditory response cradle.

stimulus is presented to the infant on a number ofoccasions and the resulting motor and respiratoryresponses are detected and stored in the memory ofthe microprocessor; equal numbers of interspersed,no sound control trials, carried out in an identicalfashion, enable calculation of the probability thatthe responses to sound are specific reactions and notspontaneous events. When this probability exceeds97% (calculated using binomial probabilitydistribution),8 the baby is considered to have normalresponses and is 'passed.' If the sound level at theprobe tip falls below 82 dB SPL or abnormalrespiratory patterns are detected, however, faultlights are illuminated on the control console and thetest is automatically inhibited, allowing user in-tervention. The auditory response cradle test is fullyautomatic and once initiated continues until thebaby 'passes' or 'fails'. ('Failure' is used in this paperto identify those babies who do not achieve the 97%confidence level. On the auditory response cradlethis is indicated by a 'refer' light illuminating on thecontrol console.) Once the baby is settled, the test iscompleted in two to 10 minutes.Neonates failing the auditory response cradle

screen are retested on a separate occasion duringtheir hospital stay as it is necessary to eliminatethose who fail the first screen because of unrespon-siveness which may be unrelated to deafness (forexample deep sleep, jaundice, or traumatic de-livery). Babies in special care units are tested ontheir discharge from the unit.The study presented in this paper is an evaluation

by long term follow up of the effectiveness of the

auditory response cradlehearing in neonates.

as a device for screening

Method

Subjects. A total of 5553 newborn infants (weight2-27 to 5 kg) have been tested in the auditoryresponse cradle to date. Some 4861 of the 5553babies have been followed up at the age of 7 to 9months by a clinic hearing screen, 2853 have beenfollowed up at 18 months by questionnaire, and 1026have been followed up by a further questionnaire atthe age of 3 years. Babies are tested in the auditoryresponse cradle at any time during their hospitalstay, although it has been found that waiting until atleast two days after birth and using the period onehour after a feed to one hour before the next feedensures a more settled baby. The mother isapproached on the ward to obtain informed consentand the nursery nurse, who carries out the test,completes a questionnaire which helps to determinewhether or not the baby is 'at risk' for deafness usingthe following criteria:

(1) A history of hereditary childhood hearingimpairment.

(2) Rubella or other non-bacterial intrauterinefetal infections (for example cytomegalovirusor herpes infection).

(3) Congenital malformations of the ear, nose, orthroat.

(4) Birthweight less than 1-5 kg.(5) Hyperbilirubinaemia (342 gmoUl: 20 mg/100

ml, or more) or exchange transfusion.

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506 Bhattacharya, Bennett, and Tucker

(6) Five minute Apgar score of less than 5.While still on the ward the baby is made comfort-able, a polythene band containing the respirationtransducer15 is positioned around the abdomen overthe clothes, and the baby is swaddled to reduce thearousal state.

Test procedure. The auditory response cradle ishoused in a room at the quiet end of the antenatalward. The room is darkened with blinds and fittedwith a sound attenuating door but it is not otherwisesound treated. Once in the test room the child isplaced in the trolley mounted unit, the ear probe ispositioned gently in the external meatus, and thetest is initiated. The sound stimulus is generallypresented only to the right ear of the babies not atrisk for deafness. In the case of infants who areeither at risk (as determined from the questionnaire)or have been in the special care baby unit, thestimulus is presented to both the right and left earsindividually.

Immediate follow up. Two auditory response cradlefailures place the baby into a follow up programmecomprising a full paediatric examination, tympa-nometry and acoustic reflex measurements,'7 andauditory brainstem response testing. For the evokedresponse test, monaural broadband click stimuli arepresented to the infant at a rate of 30/secondthrough an electromagnetically shielded headphone.Approximately 2000 sweeps are averaged at eachstimulus intensity, ranging from 80 dB re adulthearing level (nHL) down to electric responsethreshold decreasing in 10 dB steps. The responsesare filtered (bandpass 0-03 to 4*5 kHz) and recordedon both X-Y plotter and floppy discs for permanentstorage. The child is subsequently 'cleared' if waveV is observed to have a normal latency down to 30dB HL for each ear. As maturation noticeably altersresponse latency and influences waveform morpho-logy in preterm infants'8 auditory brainstem re-sponse testing is not carried out until the babyreaches a conceptual age of at least 42 weeks.Conceptual age is defined here as the sum of theinfant's gestational age at birth plus his or herpostnatal age at time of test. At this early stage oflife, sedation is unnecessary and testing is begunafter the baby has been fed and is in a state ofnatural sleep. Babies who cannot attend this followup for a couple of months (due to family holidays orfamilies moving house) are sedated with a mixtureof trimeprazine (3 mg/kg) and chloral hydrate (30mg/kg).

Auditory brainstem testing and all hearing assess-ments performed on children recalled throughoutthe three year follow up programme are carried outin an anechoic chamber.

Follow up at age 7 to 9 months. Records from allinfants tested with the auditory response cradle,with the exception of those whose deafness has beenconfirmed, are sent to the district health authoritywho subsequently return the results of their de-velopmental 7 to 9 month clinic hearing screeningprogramme. An unconditioned sound lateralisationtechnique (distraction testing) is used for correlationwith the neonatal screen. Babies that fail arereferred to their local audiology centre and all testresults are sent to the auditory response cradleevaluation programme. If the child does not attendthe clinic screen on two consecutive occasions afollow up questionnaire, enclosing a prepaid replyenvelope, is sent to the mother with questions aboutthe child's babble, awareness of sounds, and historyof ear infections. Any suspicion of hearing lossarising from the returned form results in recall fortympanometry and acoustic reflex measurementsand distraction testing.

Follow up at age 18 months. The subsequent followup at 18 months takes the form of a questionnaire(enclosing a prepaid reply envelope) which is sent tothe mother of every baby originally tested in theauditory response cradle except those already con-firmed as being deaf. The following questions areincluded in this questionnaire:

(1) Do you have any reason to be concerned thatyour child may have a hearing loss? If so,please explain why.

(2) Does your child turn to find sounds?(3) Does your child have a vocabulary of five to 6

words?(4) Does your child appear to have good balance?

The child is recalled for hearing assessment if themother replies 'Yes' to question (1) or 'No' to two ormore of the remaining questions. At this assessmentimpedance testing is routinely employed and distrac-tion testing is carried out using conventional stimuli,namely cup and spoon, sibilant 'ss', high frequencyrattle, and voicing at low frequencies. The child issaid to have hearing within normal limits if aresponse is obtained to all stimuli at a minimal levelof 30 dB HL for each ear. Information at specificfrequencies is obtained with a Linco AU2 warbletone generator and a Peters AP22 free field audio-meter. Visual reinforcement audiometry employingpure tones is carried out where entirely satisfactoryresponses to the distraction test are not given. Thevisual reinforcement auditory system consists of twoillluminating stationary toys each placed at an angleof 45 degrees to the child. Testing is controlled fromthe anteroom and the child's responses are moni-tored by a high contrast 8 inch video monitor.

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Follow up at age 3 years. The final follow up whenthe child is 3 years old again takes the form of a

questionnaire which includes the following ques-tions:

(1) Do you have any reason to be concerned thatyour child may have a hearing loss? If so,please explain why.

(2) Does your child speak in sentences easilyunderstood by friends and relatives?

(3) Does your child have good balance?(4) Has your child had a hearing test other than at

birth or the one given at 7 to 9 months by thechild health clinic? If so, please explain thereason for the test and the result.

The child is recalled for hearing assessment if thereplies are 'Yes' to question (1), 'No' to questions(2) or (3), or if the answer to question (4) or any

additional comments on the returned questionnaireare at all suggestive of hearing loss. The battery oftests carried out at this recall include pure toneheadphone audiometry using an Oscilla TS3-7audiometer and a speech discrimination test(McCormick Toy test)'9 in the anechoic chamber,along with tympanometry, acoustic reflex measure-

ments, and otoscopy. The child is said to havehearing within normal limits if:

(a) The threshold for air conduction is less than 20dB HL at 0-5 to 4 kHz, and less than 30 dB HLat 8 kHz in each ear.

(b) The audiogram is supported by the speechdiscrimination test with 100% discriminationbeing obtained at a minimal level of 40 dBHL.

The results of all hearing assessments carried out ateach stage of the auditory response cradle follow up

programme are sent to the consultant paediatricianand district health authority.

Results

The results of the screening trials are shown inTables 1 to 4. Table 1 provides the basic pass/referstatistics. Of the original 5553 neonates tested 439(7-9%) failed the first screen but this figure wasreduced to 88 (1-6%) after the second test. Sixty oneof the 88 babies referred for follow up by auditorybrainstem response and impedance testing were

subsequently cleared, giving a false positive rate of1-1%.

Table 1-first time failures. Nine newborns whofailed the first auditory response cradle test were

discharged from hospital before they could be testedagain. One child returned three weeks later and was

found to have serous otitis media, which was treatedmedically. He was subsequently tested elsewherewith electrocochleography and no action potential

Table 1 Results ofauditory response cradle trials

Tested

Failed first test

Failures discharged before retestSevere bilateral S/N lossHigh frequency S/N lossCleared by child health clinicCleared by questionnaire

Retested

Passed at second test

Failed first and second testsSevere bilateral S/N lossSeverr unilateral S/N lossModerate unilateral S/N lossSerous otitis mediaAuditory brainstem responise

abnormalityMicrocephalicDevelopmentally immatureLost to follow up

Awaiting resultsSubsequently cleared

(1),(6)(I)

5553

439 (7.9%)9

430

342

88 (1-6% )(5)(1)(1)(3)

(3)(1)(1)(I)

(11)(61)

False positive rate (61 of 5553) 11-l/

'Same babies in Tables 1, 2. and 4.

was observed. The child is now 3 years old andwears two Phillips 8146 hearing aids (volume setting5). Unaided, localising responses were obtained to adrum and xylophone at 100 to 110 dB HL and aided,the following responses were obtained bilaterally-55 dB HL at 250 Hz and 500 Hz; 65 dB HL at 1 kHz;no response at 2 kHz and 4 kHz.The second child did not return for the repeat

auditory response cradle test and information wasnext obtained via the three year questionnaire whichdescribed him as having poor speech development.He lived too far away to attend a recall, but resultsfrom his local audiology clinic showed him to have aprofound high frequency hearing loss. Of theremaining 7 infants who did not attend for retest, 6were cleared at the 7 to 9 month child health clinicscreen, and the child who did not attend this clinicscreen was subsequently cleared by both the 18month and three year questionnaires.

Table 1-second time failures.(a) Sensorineural lossesThe second test failures included five babies withbilateral and two with unilateral sensorineurallosses. The average auditory brainstem responsethreshold for those with bilateral sensorineurallosses was equal to or greater than 80 dB HL. Allfive children have now been issued with hearingaids. The child with a severe unilateral loss hadnormal brainstem responses for the left ear down toa stimulus level of 40 dB HL, but no responses couldbe detected on the right for a stimulus level up to 80dB HL. The child moved out of the area just beforehe was due to attend the age 7 to 9 months hearing

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screen and we are currently awaiting the detailedresults of the distraction test carried out by his localchild health clinic, which has confirmed a loss in theright ear. The child with a moderate unilateralhearing loss had abnormal auditory brainstem re-

sponse on the left and no detectable response on theright up to a stimulus level of 80 dB HL. Hesubsequently passed the 7 to 9 months clinic hearingscreen but was nevertheless recalled for furtherassessment because of the distraction test/auditorybrainstem response disparity. Normal middle ear

function was obtained on impedance testing but on

distraction testing he was found to have a thresholdof 30 dB HL for all frequencies on the left ear and a

moderate hearing loss on the right ear (60 dB HL at500 Hz, 1 kHz, 2 kHz; greater than 90 dB HL at4 kHz).

(b) Middle ear pathologiesThere were three newborns in whom brainstemevoked response testing showed a hearing loss whichwas found by tympanometry and acoustic reflextesting to be due to secretory otitis media.

(c) Brainstem latency and rate abnormalitiesThree brainstem latency and rate abnormalitieshave been detected. One infant who was resusci-tated after apnoea and asystole showed poor audi-tory brainstem response bilaterally. The child now

suffers from severe spastic quadriplegia and as he isstill in hospital care at the age of 18 months, no

further hearing assessment has been possible. Thesecond child was born 6 weeks preterm, severelyjaundiced, and had been in intensive care for a weekas a result of episodes of apnoea. When tested in theauditory response cradle his left ear was normal butabnormal responses were obtained on the right. Nobrainstem responses could be detected for the rightear up to a stimulus level of 80 dB HL andimpedance testing showed middle ear dysfunction.Further tests are currently being carried out todetermine whether this is a conductive, sensorineu-ral, or mixed loss. The third infant was 11 weekspreterm (weight 1-2 kg) and was tested in theresponse cradle at 5 months of age (weight 3-6 kg)after a stormy neonatal period. No auditory brain-stem response could be detected for either ear.

Results of the local child health clinic assessment are

awaited.

(d) Other abnormalitiesOne of the babies who failed the auditory responsecradle test was microcephalic. There was no indica-tion of any high risk factors and on auditorybrainstem response test normal latencies were

obtained for wave V for both ears down to a

stimulus level of 40 dB HL. The child's elec-troencephalographic trace, however, which is con-tinuously monitored throughout evoked responseaudiometry, seemed abnormal and a full paediatricassessment diagnosed him as microcephalic.Another infant who failed the auditory responsecradle test was found to have abnormal brainstemresponses for both ears at 8 weeks of age. Ondistraction testing at 8 months, poorly localised 45 to50 dB HL responses were obtained and impedancetesting showed bilateral secretory otitis media. As itwas unclear whether the poor localisation was due todevelopmental immaturity or a sensorineural losswith conductive overlay, the child is awaitingdefinitive diagnosis.

(e) Lost to follow upOnly one baby who failed the test was lost to followup during the neonatal period. This family isdifficult to trace due to mobility relating to thefather's occupation.

(f) Awaiting resultsEleven infants are currently awaiting follow up.

Table 2-follow up at age 7 to 9 months. After theauditory response cradle screen, follow up is carriedout at 7 to 9 months of age by the child health clinic.As shown in Table 2, 4861 infants tested at birthhave now reached this age. One of the 3970 babiesthat attended and passed this screen had previouslyfailed the cradle test and auditory brainstem re-sponse follow up. He was recalled for further

Table 2 Results of child health clinicfollow up at 7 to9 months ofage

Number of subjects

Passed+

FailedSevere bilateral S/N loss (previouslyhaving failed ARC test) (1)*Severe bilateral S/N loss

(initially passedARC test but thought to have

a progressivehereditary deafness) (1)Cleared-including 3 with

serous otitis media (5)

Gross loss to follow upNo information availableMother refused testNon-attendanceMoved with no forwarding addrcssMoved out of follow up area

DiedAdopted

Less replies to letter

Net loss to follow up

285 (6-0%)14 (0(3%)

256 (5-3%)188 (3-9%)123 (2-5%)14 (0(3%)4 (0-1%)

4861

397(0 (81-7%Y)7 (01%)

884 (18-4%)

333 (6-9%)

551 (11-3%)

* *Same children in Table 1.

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assessment and was found to have a responsethreshold at 30 dB HL for all frequencies on the leftand a moderate sensorineural loss on the right (60dB HL at 500 Hz, 1 kHz, 2 kHz; greater than 90 dBHL at 4 kHz).

Seven babies failed the clinic hearing screen; onehad previously failed the auditory response cradletest and had subsequently been proved deaf and 6infants had passed the response cradle test. One ofthese 6 was tested by electrocochleography at 14months of age and was found to have a severebilateral sensorineural loss. This is believed to beevidence of a hereditary progressive loss as an eldersibling has been exhibiting a similar loss for 7 years.The remaining five babies passed when tested again;three of them had secretory otitis media. (Manymore than three children actually failed the 7 to 9month screen due to secretory otitis media but wererecorded by the child health clinic as having passedif the middle ear dysfunction had resolved whenthey were tested again).

Despite exhaustive follow up, 884 babies (18-4%)have been lost at this stage of the programme.Reasons for failing follow up are listed in Table 2.The largest group is the 'no information available'group which includes babies for which no test resultshave been received. The district health authoritypresumed that they had not attended clinic or hadmoved. No further follow up was carried out by theclinic as these children were by then well over 18months old. The number of losses from this group isreduced by subtracting the number of 18 month or 3year questionnaires that have been returned withsatisfactory replies. The losses due to 'moved out offollow up area' are reduced in the same manner bysubtracting from the number of 18 month or 3 yearquestionnaires returned with satisfactory replies.Another large group of losses is that of 'nonattendance' and represents the children who did notattend the clinic screen on two consecutive oc-casions. This number is also reduced by the followup questionnaire.

Table 3-follow up at 18 months of age. A total of2853 questionnaires have been sent out to childrenwho have reached 18 months of age and 2045 (72%)have been returned (Table 3). Nineteen of the 26babies recalled were cleared and 7 were found tohave middle ear dysfunction (secretory otitis media)and were referred through the consultant paediatri-cian and senior clinical medical officer for appropri-ate treatment.Thus far no false negatives (that is babies who

passed the auditory response cradle test but actuallyhave a hearing impairment) have been foundthrough the 18 month questionnaire.

Table 3 Results of18 month follow up programme viaquestionnaire

Number of questionnaires sent 2853Number returned 2045 (72%)Number giving satisfactory replies to hearing.

balance and vocabulary questions 2019Number recalled 26Number cleared (19)Serous otitis media (7)

Table 4 Results of3 yearfollow up programme viaquestionnaire

Number of questionnaires sent 1026Number returned 654 (64%)Number giving satisfactory replies

to hearing, balance andvocabulary questions 629

Number recalled 25Cleared (16)Serous otitis media (8)High frequency S/N loss (1)'

*Same baby in Table 1.

Table 4-follow up at 3 years of age. The last stage ofthe follow up programme occurs when the babyreaches the age of 3 years and the final question-naire is sent to the mother. To date 1026 question-naires have been sent of which 654 (64%) have beenreturned (Table 4). As a result of the 25 question-naires returned with unsatisfactory replies, 24 chil-dren have been recalled; 16 of these children havebeen cleared and 8 were found to have middle eardysfunction (secretory otitis media). The remainingchild was shown by his local audiology clinic to haveno high frequency hearing on pure tone headphoneaudiometry. This child had failed the auditoryresponse cradle test once in the neonatal period (seeTable 1) and had not returned for a retest. As helived outside the district health authority area noresults from a 7 to 9 month hearing screen had beenobtainable and the mother had not replied to the 18month questionnaire. He was eventually picked upvia the 3 year questionnaire because of poor speechdevelopment.

Discussion

Because of the low incidence of congenital hearingloss very large numbers of subjects are required tovalidate fully any screening device. The figurerecommended by the Department of Health is thatof 6000 children to be followed to the age of 3 years.

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Thus far nearly 5000 infants have been followed toage 9 months, 3000 to age 18 months, and 1000 to 3years and the indications to date are most promis-ing. The false positive rate of 1-1% is acceptably lowfor a screening device and compares favourably withthat reported by Shepard20 in a 'modified massscreening programme'.

The cradle was designed to detect moderate andsevere non-recruiting hearing losses and as shown inTable 1, 12 infants have been confirmed as having ahearing impairment. The detection of unilateralsensorineural loss was not one of the aims of theresearch programme as this condition does notaffect the acquisition of speech and languageappreciably. As the sound stimulus was presented toone ear only in most infants tested, it follows thatonly approximately 50% of unilateral losses will bedetected; in practice two neonates with a unilateralloss have been found.The finding of three neonates with serous otitis

media has important implications. In the trials withthe prototype apparatus'4 it was found that neonateshave a very sharply defined behavioural threshold toacoustic stimuli. This varied with the type ofstimulus used and was measured to be 72 dB forbroad band noise. In each case the reduction of theintrameatal sound pressure level by 5 dB below thisthreshold caused the response rate to fall to that ofthe 'no sound' control trials. This behaviouralreaction can be likened to a simple muscle reflex, forexample the stapedius reflex. Because of this it wasoriginally hypothesised that if the test sound levelwas set at 15 dB above the measured threshold,infants with losses in excess of this would have theirresponse rate reduced to the control value andwould fail the auditory response cradle test. It wasconsequently expected that both moderate andsevere losses could be detected by the screen. Thepresence of the three babies with middle eardysfunction in the fail group seems to support thehypothesis, as hearing losses from this condition ofgreater than 40 dB are unlikely and cannot begreater than 60 dB on a pure transmission basis.As previously described, babies confirmed deaf

within the first few months of age did not attendtheir local child health clinic at age 7 to 9 months asthey were referred to specialist audiology units. Forthis reason only one baby is shown in Table 2as having previously failed the auditory responsecradle test.

Follow up losses in screening programmes areinevitable. During the neonatal period only one ofthe 89 infants recalled for testing (Table 1) was lostto follow up. At this stage of the programme, losseswere kept to a minimum by providing transport forany mother and child otherwise unable to attend.

After the neonatal period the loss to follow upincreased considerably-18-3% at 7 to 9 months;28% at 18 months; 36% at 3 years. The gross loss of18-3% was reduced to a net loss of 11-3% by meansof questionnaires as described previously. This is amore satisfactory figure and represents a follow uploss mainly due to families who have moved and leftno forwarding address. At the 18 month and 3 yearfollow up, the attendance rate of children recalledwas 100% as transport was provided whenevernecessary. The follow up losses at these two stagesof the programme were almost entirely due tofamilies having moved. The increasingly greater lossto follow up with time in this evaluation studyreinforces the need to screen when the largestproportion of the population is available-in thenewborn nursery. A programme is currently beingcarried out to trace all children via their familydoctor, the community health service, and the localhousing department.The auditory response cradle validation study will

be complete when every neonate originally testedwith the cradle has been followed up to the age of 3years. The infants who failed the cradle test butwere subsequently cleared are being kept undercareful review and will all be recalled for pure toneheadphone audiometry, impedance testing, and aspeech discrimination test. It is anticipated thatthese goals will have been achieved by 1986. Anumber of other centres are now equipped with theauditory response cradle and further validation willbe forthcoming.

This study is funded by a grant from the Department of Health andSocial Security and all work is carried out at Brunel University andHillingdon Hospital.

References

Marlowe JA. Hearing in infancy: The development of auditoryskills and the audiological evaluation. Seminars in SpeechLanguage and Hearing 1982;3:28-44.

2 Morrison MD, Brewster L. Early detection of childhoodhearing impairment-problems and possible solutions. J Oto-laryngol 1978;7:484-9.

3 Swift EW, Swift WI, Camp BW, Silvern LW. Predictive valueof early testing of auditory localization for language develop-ment. Dev Med Child Neurol 1981;23:306-12.

4 Hirsh IJ. Psychological aspects of early auditory education.J R Soc Med 1982;3:28-44.

5 Downs MP. Auditory screening. Otolaryngol Clin North Am1978;11:611-29.

6 Simmons FB, McFarland W, Jones FR. Automated hearingtechniques for newborns. Acta Otolarngol (Stockh) 1979;87:1-8.

7 Stockard JE, Stockard JJ, Kleinburg F, Westmoreland BF.Prognostic value of brainstem auditory evoked potentials inneonates. Arch Neurol 1983;40:360-5.

8 Jacobsen JT, Morehouse CR, Johnson MJ. Strategies for infantauditory brainstem response assessment. Ear and Hearing1982;3:263-70.

9 Bernheimer L, Keaster J, Linthicum FH. Neonatal hearingscreening. California Medicine 1972;116:5-8.

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10 Flood LM, Fraser JG, Conway MJ, Stewart A. Assessment ofhearing in infancy using the post-auricular myogenic response.Br J Audiol 1982;16:211-4.Ventry IM. Computing false positive and false negative rates forthe Crib-o-gram. J Speech Hear Disord 1982;47:109-10.

2 Bennett MJ. The auditory response cradle: a device for theobjective assessment of auditory state in the neonate. In:Bench RJ, Rye A, Pye JD, eds. Sound reception in mammals.London: Academic Press, 1975.

13 Bennett MJ, Wade HK. Automated newborn screening usingthe auditory response cradle. In: Taylor IG, Markides A, eds.Disorders of Auditory Function. III. London: Academic Press,1980.

14 Bennett MJ. Trials with the auditory response cradle I: neonatalresponses to auditory stimuli. Br J Audiol 1979;13:125-34.

15 Bennett MJ. Trials with the auditory response cradle II: theneonatal respiratory response to an auditory stimulus. Br JAudiol 1980;14:1-6.

16 Bennett MJ. Trials with the auditory response cradle III: headturns and startles as auditory responses in the neonate. Br JAudiol 1980;14:122-31.

17 Weatherby LA, Bennett MJ. The neonatal acoustic reflex.Scand Audiol 1980;9:103-10.Weber BA. Comparison of auditory brainstem response latencynorms for premature infants. Ear and Hearing 1982;3:257-62.

19 McCormick. An aid for screening the hearing of young children.Public Health 1977;91;67-73.

20 Shepard NT. Newborn hearing screening using the Linco-Bennett auditory response cradle: a pilot study. Ear and Hearing1983;4:5-10.

Correspondence to Dr S M Tucker, Department of Paediatrics,Hillingdon Hospital, Uxbridge, Middlesex.

Received 6 February 1984

British Paediatric Association

Annual meetings

1985 16-20 April York University1986 15-19 April York University1987 7-11 April York University

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Documents

Long term auditory response · automatic and once initiated continues until the baby'passes' or'fails'. ('Failure' is usedin thispaper to identify those babieswhodonotachievethe97%