Vestibular Rehabilitation Using Dynamic Posturography: Objective and Patient-Reported Outcomes from a Randomized Trial.

OBJECTIVE: Balance deficits are common and debilitating. Standard treatments have limitations in addressing symptoms and restoring dynamic balance function. This study compares a rehabilitative computerized dynamic posturography (CDP) protocol, computerized vestibular retraining therapy (CVRT), with a home exercise program (HEP) for patients with objectively confirmed unilateral vestibular deficits (UVDs). STUDY DESIGN: Single-center, randomized, interventional trial, with 1-sided crossover. SETTING: A tertiary neurotology clinic. METHODS: Patients with UVDs and Dizziness Handicap Inventory (DHI) score >30 were randomized to receive either CVRT or HEP. After completion of treatment, the HEP group was crossed over to CVRT. Outcome measures were the sensory organization test (SOT) and 3 participants reported dizziness disability measures: the DHI, Activity-Specific Balance Confidence Scale (ABC) scale, and Falls Efficacy Score-International (FES-I). RESULTS: We enrolled 37 patients: 18 participants completed CVRT and 12 completed HEP, 11 of whom completed the crossover. Seven participants withdrew. The CVRT group demonstrated a greater improvement in SOT composite score than the HEP group (P = .04). Both groups demonstrated improvement in participant-reported measures but there were no differences between groups (DHI: P = .2604; ABC: P = .3627; FES-I: P = .96). Following crossover to CVRT after HEP, SOT composite (P = .002), DHI (P = .03), and ABC (P = .006) improved compared to HEP alone. CONCLUSION: CVRT and HEP were both associated with improved participant-reported disability outcomes. CVRT was associated with greater improvement in objective balance than HEP. Adding CVRT after HEP was superior to HEP alone. Multimodal CDP-based interventions, such as CVRT, should be considered as an adjunct to vestibular physiotherapy for patients with UVD.

Dynamic posturography after computerized vestibular retraining for stable unilateral vestibular deficits.

BACKGROUND: Balance deficits increase the risk of falls and compromise quality of life. Current treatment modalities do not resolve symptoms for many patients. AIMS/OBJECTIVES: To measure changes in objective posturography after a computerized vestibular retraining therapy protocol. MATERIALS AND METHODS: This was a single-arm interventional study of individuals with a stable unilateral vestibular deficit present for greater than six months. Participants underwent 12 twice-weekly sessions of computerized vestibular retraining therapy. Objective response was measured by the Sensory Organization Test and questionnaires were administered to measure subjective changes. RESULTS: We enrolled 13 participants (5 females and 8 males) with a median age of 51 years (range 18 to 67). After retraining, the Sensory Organization Test composite score improved by 8.8 (95% CI 0.6 to 19.1) and this correlated with improvement in the Falls Efficacy Scale-International questionnaire (rs -0.6472; 95% CI -0.8872 to - 0.1316). Participants with moderate-to-severe disability at baseline (n = 7) demonstrated greater improvement in the composite score (14.6; 95% CI 7.0 to 36.9). CONCLUSIONS AND SIGNIFICANCE: Computerized vestibular retraining therapy for stable unilateral vestibular deficits is associated with improvement in dynamic balance performance. Posturography improvements correlated with a reduction in perceived fall risk. Trial Registration Information Clinicaltrials.gov registration NCT04875013; 04/27/2021.

Erratum: The Rise and Fall of Aural Acoustic Immittance Assessment Tools.

[This corrects the article DOI: 10.1055/s-0043-1764139.].

The Rise and Fall of Aural Acoustic Immittance Assessment Tools.

Clinical assessment of middle ear function has undergone multiple transformations and developments since the first acoustic impedance measurements were made in human ears nearly a century ago. The decades following the development of the first acoustic impedance bridge by Metz in 1946 witnessed a series of technological advancements leading to the widespread use of single-frequency admittance tympanometry in the 1960s. In the 1970s, multi-frequency and multi-component tympanometry (MFT) emerged for clinical use, allowing for a better understanding of the middle ear acoustic-mechanical response at frequencies between 200 and 2,000 Hz. MFT has not gained widespread clinical adoption despite its advantages over single-frequency tympanometry. More recent technological developments enabled assessment for frequencies greater than 2,000 Hz, leading to the advent of wideband acoustic immittance measures with capabilities for comprehensive assessment of middle ear acoustic mechanics, and a great potential for use of acoustic immittance testing in various diagnostic practices. This article reviews important historical markers in the development and operation of middle ear assessment tools and analysis methods. Technical and clinical factors underlying the emergence and adoption of different acoustic immittance tests as a standard of clinical practice are described. In addition, we discuss the likelihood for widespread adoption of wideband acoustic immittance and wideband tympanometry in future clinical practice.

Wideband Acoustic Immittance in Children.

As wideband absorbance (WBA) gains popularity, it is essential to understand the impact of different middle ear pathologies on the absorbance patterns as a function of frequency in children with various middle ear pathologies. More recently, the use of wideband tympanometry has enabled clinicians to conduct WBA at ambient pressure (WBA amb ) as well as the pressurized mode (WBA TPP ). This article reviews evidence for the ability of WBA measurements to accurately characterize the normal middle ear function across a wide range of frequencies and to aid in differential diagnosis of common middle ear disorders in children. Absorbance results in cases of otitis media with effusion, negative middle ear pressure, Eustachian tube malfunction, middle ear tumors, and pressure equalization tubes will be compared to age-appropriate normative data. Where applicable, WBA amb as well as WBA TPP will be reviewed in these conditions. The main objectives of this article are to identify, assess, and interpret WBA amb and WBA TPP outcomes from various middle ear conditions in children between the ages of 3 and 12 years.

Durable improvement in participant-reported measures of disability and objective posturography after computerized vestibular retraining.

BACKGROUND: Unilateral vestibular deficits are associated with postural instability and loss of quality of life. Common treatments frequently fail to achieve satisfactory outcomes. OBJECTIVE: To assess the durability of changes in participant-reported disability and objective posturography after computerized vestibular retraining. METHODS: This was a single-group study. Individuals with persistent symptoms of an objectively determined unilateral vestibular deficit completed questionnaires and posturography assessments before and after twelve sessions of computerized retraining, and 4-6 months and 10-12 months after treatment. RESULTS: 13 participants completed the post-treatment assessments; 9 completed the follow up. Mean improvements in perceived disability at 4-6 months after retraining were: DHI 14.3 points (95% confidence interval 4.0 to 24.5), ABC scale 14.9 points (4.3 to 25.6), FES-I 11.6 points (-3.2 to 26.5).The SOT composite score increased by 11.4 points (95% CI 1.9 to 20.9; p = 0.0175) immediately after treatment, 8.9 points (-2.9 to 20.7; p = 0.1528) at 4-6 months, and 10.6 points (2.2 to 19.0; p = 0.0162) after 10-12 months. At the 10-12 month time point, the areas of the functional stability region increased significantly for both endpoint excursion (p = 0.0086) and maximum excursion (p = 0.0025). CONCLUSION: Computerized vestibular retraining was associated with improved participant reported disability and objective measures of postural stability.

Patient-Reported Disability After Computerized Posturographic Vestibular Retraining for Stable Unilateral Vestibular Deficit.

Importance: Individuals with persistent unilateral vestibular deficits experience loss of quality of life and increased risk of falling, and they have few well-supported options for effective treatment. Objectives: To evaluate whether vestibular retraining using computerized dynamic posturography is associated with reduced participant-reported disability for patients with an objectively assessed unilateral peripheral vestibular deficit and to assess the feasibility of conducting a randomized clinical trial of vestibular retraining using computerized dynamic posturography. Design, Setting, and Participants: This single-group cohort study was conducted from April 29 to July 23, 2021, in a tertiary neurotology clinic among 13 individuals with a stable unilateral vestibular deficit present for more than 6 months, confirmed with videonystagmography and vestibular evoked myogenic potential testing. Statistical analysis was performed from July 7, 2021, to January 25, 2022. Interventions: Twelve twice-weekly sessions of posturography-assisted vestibular retraining with prescribed weight shifting tasks guided by an interactive display. Main Outcomes and Measures: Change in scores on the Dizziness Handicap Inventory (DHI), the Activities-Specific Balance Confidence (ABC) Scale, and the Falls Efficacy Scale-International (FES-I), which participants completed before and after retraining to measure their perception of their disability. They also completed posturography measurements. Secondary outcomes included tolerability of the intervention and rate of completion of the full protocol. Results: A total of 13 participants (8 men [62%]; median age, 51 years [range, 18-67 years]) were enrolled. All 13 participants completed the intervention and all follow-up. After treatment, the median changes in scores were -16 points (95% CI, -20 to 2) for the DHI, -9 (95% CI, -14 to 1) for the FES-I, and 11.9 (95% CI, 0-17.3) for the ABC Scale. Eight participants (62%) improved by greater than the minimum clinically important difference (MCID) for the DHI, whereas 4 (31%) exceeded the MCID for the ABC Scale, and 3 (23%) exceeded the MCID for the FES-I. Participants with moderate to severe disability at baseline (n = 7) had a larger magnitude of improvement in DHI scores than those with mild disability (n = 6) (-18 [95% CI, -78 to 2] vs -1 [95% CI, -8 to 16]). Six of the 7 patients (86%) with moderate to severe disability improved by greater than the MCID for DHI, wherease 4 of 7 patients (57%) improved by greater than the MCID for the ABC Scale, and 3 of 7 patients (43%) improved by greater than the MCID for the FES-I. Conclusions and Relevance: This cohort study suggests that computerized, dynamic posturography-assisted retraining was associated with clinically meaningful improvements in participant-reported disability among those with stable unilateral vestibular deficit and moderate to severe disability. Further studies should compare posturography-assisted vestibular retraining with conventional physical therapy rehabilitation techniques. Trial Registration: ClinicalTrials.gov Identifier: NCT04875013.

Normal values for cervical and ocular vestibular-evoked myogenic potentials using EMG scaling: effect of body position and electrode montage.

BACKGROUND: The clinical utility of cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) is limited by variability of testing protocols and a dearth of normative data using contemporary methods for amplitude scaling. AIMS/OBJECTIVES: To investigate the effect of body position and electrode montage on VEMP responses and to establish normative values. MATERIAL AND METHODS: This is a repeated measures study of 44 healthy young adult subjects (22 men and 22 women). RESULTS: The highest response rate (99%) for cVEMP was achieved in the supine position with the head elevated and turned. For oVEMP, the highest response rate (90%) was achieved using nasal alar electrode montage with the subject in a sitting position. Scaled peak-to-peak amplitude was higher in males than in females for both cVEMP and oVEMP. CONCLUSION: Normative data for 44 young healthy adults was successfully collected for two body positions for cVEMP and two head positions and two electrode montages for oVEMP. SIGNIFICANCE: Our findings describe VEMP protocols that efficiently detect VEMP responses, and we provide normative VEMP response data for young healthy subjects. We describe a potential difference in response between males and females, which may be clinically important.

The Audiology of Otosclerosis.

Diagnostic audiologic procedures for otosclerosis are effective tools in identifying this condition. Audiometric data usually demonstrate a conductive hearing loss at the early stages of otosclerosis. Modern middle ear analysis procedures are becoming more popular in the better diagnosis of otosclerosis. In clinical practice, cochlear otosclerosis can also be observed. Audiologic rehabilitation of otosclerosis includes fitting of hearing aids and implantable hearing devices. Current hearing technology enables patients who do not pursue surgical correction to function well and significantly improve their communication and quality of life. Otosclerosis may also be associated with annoying tinnitus, and tinnitus management is important in the rehabilitation process.

Wideband acoustic immittance measurements in assessing crimping status following stapedotomy: A temporal bone study.

OBJECTIVE: To ascertain if wideband acoustic immitance (WAI) measurements are useful in assessing crimping status following stapedotomy. DESIGN: WAI measurements were obtained using the Mimosa Acoustics HearID system. Wideband chirp sound stimuli and a set of tone stimuli for nine frequencies between 0.2 and 6 kHz were used at 60 dB SPL. Five sets of measurements were performed on each temporal bone: mobile stapes, stapes fixation and stapedotomy followed by insertion of a tightly crimped, a loosely crimped and an uncrimped prosthesis. STUDY SAMPLE: Eight fresh-frozen temporal bones were harvested from human cadaveric donors. RESULTS: At lower frequencies, up to 1 kHz, stapes fixation decreased absorbance. Compared to the baseline absorbance, absorbance with stapes fixation dropped by 6 to 17% in absolute terms from the baseline value (p = 0.027). Absorbance was not affected in higher frequencies (p = 0.725). Stapedotomy changed the absorbance curve significantly compared to the normal condition with an increase of absolute absorbance values by 6 to 36% around 0.25-1 kHz (p-value <0.01). The crimping conditions did not differ from one another (p = 0.555). CONCLUSION: WAI is not useful in distinguishing between tightly crimped, loosely crimped and uncrimped stapes prostheses following stapedotomy.

Wideband reflectance in Down syndrome.

OBJECTIVE: Children with Down syndrome (DS) have a high incidence of middle ear disorders and congenital abnormalities of the external, middle and inner ear. Energy reflectance (ER), a wideband acoustic immittance (WAI) measurement parameter, can measure the sound energy reflected or absorbed in the ear canal over a wider range of frequencies more efficiently and faster than conventional single-tone 226 Hz tympanometry. The aim of the present study was to compare the WAI measurements of children with DS with those of typically developing, normal-hearing children according to their tympanometric findings. METHODS: Four groups of children with Down syndrome (age range: 2 years and 4 months to 16 years and 3 months; mean age: 8.5 yr) with normal tympanograms (19 ears), flat tympanograms (13 ears), mild negative pressure tympanograms (6 ears between -100 and -199 daPa at the admittance peak) and severe negative pressure tympanograms (4 ears at -200 daPa or lower at the admittance peak) were assessed. All findings were compared with data obtained from 21 ears of a healthy control group (age range: 3 years and 1 month to 13 years and 11 months; mean age: 7.9 yr). The subjects underwent tympanometry with a 226-Hz probe tone frequency and ER measurements along the 200-6,000 Hz range with a chirp stimulus using the Middle-Ear Power Analyzer (MEPA3 - HearID) by Mimosa Acoustics (Champaign, IL), software, version 3.3 [38]. RESULTS: Statistically significant differences were observed in the ER curves for some comparisons between the studied groups. There was also a negative correlation between the static acoustic admittance at the tympanic membrane level and ER measured with a chirp stimulus at 500 and 1,000 Hz. The discriminant analysis technique, which used a chirp stimulus at 1,000 and 1,600 Hz to classify the participants' data based on ER values, achieved a correct classification rate of 59.52% for participants with DS. CONCLUSION: While groups with abnormal middle ear status, as indicated by tympanometry, showed higher ER values compared to the DS tymp A group and the control group, similar reflectance curves were observed between control group and the DS tymp A group. WAI shows promise as a clinical diagnostic tool in investigating the impact of middle ear disorders in DS group. However, further research is required to investigate this issue in narrower age range group and a larger sample size.

Understanding the developmental course of the acoustic properties of the human outer and middle ear over the first 6 months of life by using a longitudinal analysis of power reflectance at ambient pressure.

BACKGROUND: As shown by tympanometric and wideband acoustic immittance (WAI) measures, developmental changes that occur in the middle ear and the external auditory canal can affect the mechano-acoustic properties of the middle ear system during the first 2 years of life. However, these observed differences and the specific course of maturation have not been fully investigated. PURPOSE: The overall goal of the current study was to define the time course and rate at which functional maturation of the middle ear occurs in human infants through wideband acoustic immittance (WAI). It was also within the scope of this study to establish normative data to characterize acoustic properties of the normal middle ear in infants from birth to 6 mo of age. RESEARCH DESIGN: Newborns were tested longitudinally at 1-mo intervals up to 6 mo of age for a total of six visits. All babies passed transient evoked otoacoustic emission screening on each visit. Tympanograms and WAI were recorded, and the distributions of WAI patterns were analyzed as a function of age. WAI was measured across a wide range of frequencies from birth to 6 mos of age in a cohort of 31 infants. Test-retest differences for WAI were also evaluated. STUDY SAMPLE: Thirty-one newborns were recruited. DATA COLLECTION AND ANALYSIS: A repeated-measure analysis of variance was conducted to investigate whether the variations observed in power reflectance at ambient pressure across the six visits were statistically different. All significant findings were subject to Greenhouse-Geisser correction for repeated-measures sphericity and inflated type-I error. RESULTS: RESULTS showed that power reflectance increased (closer to 1) at low frequencies (<400 Hz) and decreased (closer to 0) at high frequencies (>2000 Hz) as a function of age. There was very little change in power reflectance from 600 to 1600 Hz across the first 6 mo of life. Most group changes that were observed were also consistently shown in longitudinal changes observed within individual subjects. CONCLUSIONS: The overall maturation of the middle ear can result in a lower reflectance at higher frequencies and a higher reflectance at lower frequencies. This could be explained by known changes in ear-canal and/or middle-ear structures across this time period, which could lead to changes in mass and resistance. An increase in volume in the middle-ear cavity, reduction of middle-ear debris, and overall decrease in resistive elements might be contributing to these changes. Significant differences were observed between each visit, which could warrant the use of age-specific norms when applying WAI data to infants less than 6 mo of age.

Wideband acoustic immittance normative data: ethnicity, gender, aging, and instrumentation.

This article describes the effect of ethnicity, gender, aging, and instrumentation on wideband acoustic immittance (WAI). This is an important topic to investigate as the goal of any audiological test is optimize the test's sensitivity and specificity. One way to improve the test's sensitivity and specificity is to reduce the variability of the normative data. The impact of the aforementioned demographic characteristics on WAI norms has been reviewed, and where applicable its potential impact on clinical outcome has been discussed. Overall, differences observed between Caucasian and Chinese ethnic groups in adults population may warrant the use of ethnicity-specific norms especially for detection of otosclerosis; however, these differences in the school-aged children are not large enough to warrant the use of ethnicity-specific norms. It is important to explore whether the observed differences between Caucasian and Chinese ethnic groups is due to body-size indices and whether these differences can be replicated in other East Asian ethnic groups that share similar body-size indices. The differences observed between school-aged children and adults could also potentially impact clinical decision analysis. Therefore, use of age-specific norm is recommended. The differences in WAI between different systems are not clinically significant, and the use of instrument-specific norms does not result in improved test performance at least for the detection of otosclerosis. However, measuring WAI at ambient pressure (static) or at pressure corresponding to the peak (dynamic mode) could potentially impact the normative data and may prove to be clinically useful in cases of negative and positive middle ear pressure.

Assessment of ear disorders using power reflectance.

This article describes the effect of various pathologies on power reflectance (PR) and absorbance measured in human adults. The pathologies studied include those affecting the tympanic membrane, the middle-ear ossicles, the middle-ear cavity, the inner ear, and intracranial pressure. Interesting pathology-induced changes in PR that are statistically significant have been reported. Nevertheless, because measurements of PR obtained from normal-hearing subjects have large variations and some pathology-induced changes are small, it can be difficult to use PR alone for differential diagnosis. There are, however, common clinical situations without reliable diagnostic methods that can benefit from PR measurements. These conditions include ears with a normal-appearing tympanic membrane, aerated middle-ear cavity, and unknown etiology of conductive hearing loss. PR measurements in conjunction with audiometric measurements of air­bone gap have promise in differentiating among stapes fixation, ossicular discontinuity, and superior semicircular canal dehiscence. Another possible application is to monitor an individual for possible changes in intracranial pressure. Descriptions of mechanisms affecting PR change and utilization of PR measurements in clinical scenarios are presented.

Prediction of conductive hearing loss using wideband acoustic immittance.

The purpose of this article was to review the effectiveness of wideband acoustic immittance (WAI) and tympanometry in detecting conductive hearing loss (CHL). Eight studies were included that measured CHL through air-and bone-conducted thresholds in at least a portion of their participants. One study included infants, three studies included children, one study included older children and adults, and three studies included adults. WAI identified CHL well in all populations. In infants and children, WAI in several single-frequency bands identified CHL with equal accuracy to measures of middle ear admittance using clinical tympanometry with a single probe tone (1000 Hz for infants; 226 Hz for children and adults). When WAI was combined across frequency bands, it identified CHL superior to traditional, single-frequency tympanometry. Only two studies used WAI tympanometry, which assesses the outer/middle ear across both frequency and introduced air pressure, and differing results were reported as to whether introducing pressure into the ear canal provides better identification of CHL. In general, WAI appears to be a promising clinical tool, and further investigation is warranted.

Consensus statement: Eriksholm workshop on wideband absorbance measures of the middle ear.

The participants in the Eriksholm Workshop on Wideband Absorbance Measures of the Middle Ear developed statements for this consensus article on the final morning of the Workshop. The presentations of the first 2 days of the Workshop motivated the discussion on that day. The article is divided into three general areas: terminology; research needs; and clinical application. The varied terminology in the area was seen as potentially confusing, and there was consensus on adopting an organizational structure that grouped the family of measures into the term wideband acoustic immittance (WAI), and dropped the term transmittance in favor of absorbance. There is clearly still a need to conduct research on WAI measurements. Several areas of research were emphasized, including the establishment of a greater WAI normative database, especially developmental norms, and more data on a variety of disorders; increased research on the temporal aspects of WAI; and methods to ensure the validity of test data. The area of clinical application will require training of clinicians in WAI technology. The clinical implementation of WAI would be facilitated by developing feature detectors for various pathologies that, for example, might combine data across ear-canal pressures or probe frequencies.

Wideband reflectance in normal Caucasian and Chinese school-aged children and in children with otitis media with effusion.

OBJECTIVES: Wideband reflectance (WBR) is a middle ear analysis technique that quantifies frequency-specific sound conduction over a wide range of frequencies. One shortcoming of WBR is that there is limited normative data, particularly for pediatric populations and children with middle ear pathology. The goals of this study were to establish normative WBR data for early school-aged children; to determine whether WBR differs significantly between Caucasian and Chinese children, male and female children, and children and adults (experiment 1); and to compare the normative pediatric WBR data with the WBR data obtained from children with abnormal middle ear conditions (experiment 2). DESIGN: WBR was measured from 78 children with normal middle ear status with an average age of 6.15 yrs and 64 children with abnormal middle ear status with an average age of 6.34 yrs. Control group subjects and subjects without previously diagnosed middle ear pathology were recruited from eight elementary schools in the Greater Vancouver Area. Subjects with known middle ear pathology were recruited through the British Columbia Children's Hospital Otolaryngology department. Middle ear effusion (MEE) was identified in one of the two ways. In the British Columbia Children's Hospital group, MEE was diagnosed by a pediatric otolaryngologist (OTL) using pneumatic otoscopy and video otomicroscopy. These cases (21 ears) were classified as OTL confirmed. Subjects who were assessed through screenings at their elementary schools and suspected to have MEE based on audiological test battery results including elevated air conduction thresholds, flat low- and high-frequency tympanograms, and absent transient-evoked otoacoustic emissions were classified as not OTL confirmed (21 ears). Data were statistically analyzed for effects of gender, ethnicity (Caucasian versus Chinese), age (child versus adult), and middle ear condition. WBR equipment used for this study was from Mimosa Acoustics (RMS-system, version 4.03). Data were averaged in one-third octave bands collected from 248 frequencies ranging from 211 to 6000 Hz. RESULTS: Control group subject data (experiment 1) revealed no effects of gender or ear, and their interactions with frequency were not significant. There was a significant interaction between ethnicity (Caucasian versus Chinese) and frequency. Chinese children had lower energy reflectance (ER) values over the mid-frequency range. ER was significantly different between pediatric data and previously collected adult data. Diseased group ER was significantly different among all four middle ear conditions (normal, mild negative middle ear pressure, severe negative middle ear pressure, and MEE) (experiment 2). The overall test performance of ER was objectively evaluated using receiver operating characteristic (ROC) curve analyses; it was compared across frequencies averaged in one-third octave bands. Statistical comparison of the area under ROC (AUROC) plots revealed that ER above 800 Hz (except for ER at 6300 Hz) had better test performance in distinguishing normal middle ear status from MEE compared with ER at 630 and 800 Hz. Although not statistically different from other frequencies between 800 and 5000 Hz, ER at 1250 Hz had the largest AUROC curve (sensitivity of 96% and specificity of 95%) and was selected for further analysis. Comparison of AUROC curves between WBR at 1250 Hz and static admittance at 226-Hz probe tone frequency revealed significantly better test performance for WBR in distinguishing between healthy ears and MEE. CONCLUSIONS: A preliminary set of normative ER data have been generated for a pediatric population between the ages of 5 and 7 yrs, which were significantly different from previously gathered normative adult ER data. In this study, pediatric normative data were warranted for testing children, but ethnic-specific norms were not required to detect middle ear pathology and changes in middle ear status. WBR shows promise as a clinical diagnostic tool for measuring the mechanoacoustic properties of the middle ear and the changes that result in the presence of negative middle ear pressure or MEE.

Longitudinal changes in real-ear to coupler difference measurements in infants.

BACKGROUND: The real-ear-to-coupler difference (RECD) measurement is a commonly used clinical procedure that quantifies the difference in sound pressure level between a 2 cc coupler and an individual's ear canal. The SPL levels in infant ears are highly variable and significantly higher than the SPL levels present in average adult ears, making the quantification of SPL levels in infant ears extremely important for threshold determination and fitting of amplification. It is unknown how much the RECD changes in an individual infant over time, whether that change is within test-retest reliability of the RECD measure, and whether RECD values are predictable from other outer and middle ear measures. PURPOSE: The purposes of this study were to examine longitudinal changes in RECD values in newborn infants to determine whether a significant change in RECD values takes place over a one-month period, how the change in RECD relates to test-retest variability of the measure, and whether RECD values are predictable from the infant's corrected age, or measures of static admittance and equivalent ear canal volume (EECV). STUDY SAMPLE: Fourteen infants (seven females, seven males) aged 7 to 25 days were recruited through community prenatal classes, physicians, hospital nurseries, and word of mouth. All infants had normal middle ear status. DATA COLLECTION AND ANALYSIS: Infants were tested on two separate visits, first when the infant was approximately two to three weeks old and then approximately one month later. Each visit lasted one to two hours, during which time otoacoustic emissions, 226 Hz and 1000 Hz probe-tone tympanometry, and two RECD measures were made for each ear. RESULTS: A multivariate analysis of variance revealed a significant change in RECD values over a one-month interval. Regression analyses revealed that final RECD values were partially predictable from age, initial RECD value, static admittance; and EECV. RECD test-retest variability was not large but larger than longitudinal RECD changes over a one-month period. CONCLUSIONS: It may be unnecessary to remeasure an RECD to account for changes in ear canal acoustics for repeated assessments, no more than one month apart, when the same test transducer is used. The RECD should, however, be measured at one of these assessments because RECD values are not predictable from an infant's age or measures of static admittance and ear canal volume.

Wideband energy reflectance patterns in preoperative and post-operative otosclerotic ears.

The purpose of this study was to examine patterns of energy of reflectance (ER) in preoperative and post-operative conditions in otosclerotic ears. It was also within the scope of this paper to investigate whether the changes in ER pattern post-operatively correlate to the improvement in hearing as measured by pure-tone audiometry. ER was measured in 15 surgically confirmed otosclerotic ears (mean age: 44 years) before and after the stapes surgery. The most prominent change in ER pattern following the surgery in majority of the subjects was a sharp and deep drop in ER value between 700-1000 Hz. There was also a secondary wider and smaller increase in ER value following the surgery between 2000-4000 Hz. Moreover, in most cases the drop in ER values following the surgery at low frequencies (