FORUM: Remote testing for psychological and physiological acoustics.

Acoustics research involving human participants typically takes place in specialized laboratory settings. Listening studies, for example, may present controlled sounds using calibrated transducers in sound-attenuating or anechoic chambers. In contrast, remote testing takes place outside of the laboratory in everyday settings (e.g., participants' homes). Remote testing could provide greater access to participants, larger sample sizes, and opportunities to characterize performance in typical listening environments at the cost of reduced control of environmental conditions, less precise calibration, and inconsistency in attentional state and/or response behaviors from relatively smaller sample sizes and unintuitive experimental tasks. The Acoustical Society of America Technical Committee on Psychological and Physiological Acoustics launched the Task Force on Remote Testing (https://tcppasa.org/remotetesting/) in May 2020 with goals of surveying approaches and platforms available to support remote testing and identifying challenges and considerations for prospective investigators. The results of this task force survey were made available online in the form of a set of Wiki pages and summarized in this report. This report outlines the state-of-the-art of remote testing in auditory-related research as of August 2021, which is based on the Wiki and a literature search of papers published in this area since 2020, and provides three case studies to demonstrate feasibility during practice.

Healthy Volunteers Immediately Adapt to Submental Stimulation During Swallowing.

OBJECTIVES: Transcutaneous stimulation above and below the hyoid is used to assist patients with swallowing disorders (dysphagia) but has shown different effects. Previously, infrahyoid transcutaneous stimulation lowered the hyoid and larynx resisting swallowing movement while suprahyoid stimulation had no effects on hyolaryngeal movement either at rest or during swallowing. More recently, large submental electrodes, covering the submental region, are used for swallowing therapy in combination with resistance therapy. To gain insight into the effects of these electrodes on movement during swallowing, we studied healthy volunteers using videofluoroscopy (VF). We hypothesized that submental electrical stimulation might elevate the hyoid but not the larynx increasing vestibular opening potentially reducing swallowing safety. MATERIALS AND METHODS: While undergoing VF, seven healthy volunteers (mean age 51, 5 males) swallowed 5 mL of liquid barium on at least ten trials randomly ordered across three conditions: stimulation at rest, swallowing without stimulation, and swallowing with stimulation. RESULTS: During stimulation at rest, significant (one tailed p < 0.05) anterior movement occurred in the hyoid and larynx, no superior hyoid and laryngeal movement and an increase in the distance between the hyoid and larynx. When comparing swallowing with and without submental stimulation, during stimulation volunteers significantly reduced anterior hyoid motion (p = 0.028) and increased hyoid elevation (p = 0.043) without changing anterior or superior laryngeal movement or the distance between the hyoid and larynx. CONCLUSIONS: The healthy volunteers immediately corrected for the effects of submental stimulation by reducing hyoid anterior motion and increasing superior hyoid motion without changing laryngeal motion to prevent increased vestibule opening with stimulation. This suggests that healthy volunteers had an internal schema for swallowing movement patterning with feedforward correction for the effects of stimulation.

Acoustic Reflexes in Aural Atresia Patients: Evidence of an Intact Efferent System?

OBJECTIVE: To record crossed acoustic reflex thresholds (xART's) postoperatively from patients after surgical repair of unilateral congenital aural atresia (CAA). To seek explanations for when xARTs can and cannot be recorded. We hope to understand the implications for this central auditory reflex despite early afferent deprivation. METHODS: Patients who underwent surgery to correct unilateral CAA at a tertiary academic medical were prospectively enrolled to evaluate for the presence of xART. Preoperative ARTs in the normal (non-atretic) ear, and postoperative ipsilateral ARTs (stimulus in the normal ear) and contralateral ARTs (stimulus in the newly reconstructed atretic ear; record in the normal ear) were measured at 500, 1000, and 2000 Hz. RESULTS: Four of 11 patients with normal ipsilateral reflex thresholds preoperatively demonstrated crossed acoustic reflexes postoperatively (stimulus in reconstructed ear; record from normal ear). Four other patients demonstrated normal ipsilateral thresholds preoperatively but did not have crossed reflexes postoperatively. No reflexes (pre- or postoperatively) could be recorded in 3 patients. Crossed reflex threshold is significantly correlated with the postoperative audiometric threshold. There was no correlation between ipsilateral and contralateral reflex thresholds. CONCLUSION: Crossed acoustic reflexes can be recorded from some but not all postoperative atresia patients, and the thresholds for those reflexes correlate with the postoperative pure tone threshold. The presence of acoustic reflexes implies an intact CN VIII-to-opposite CN VII central reflex arc despite early unilateral sound deprivation.

Multi-sensory (auditory and somatosensory) pre-pulse inhibition in mice.

We investigated the perception of two mechanoreceptive modalities alone and in combination: main effects and interaction between auditory and somatosensory stimulation in mice. Fifteen C57BL/6J mice between the ages of 1 and 6 months were tested three times each. Experimental design roughly followed published procedures using pre-pulse inhibition (PPI) of the acoustic startle response, except pre-pulses included vibration of the test chamber as well as soft sounds. Auditory pre-pulses were 80 dB broadband noises of 4, 9, 25, or 45 ms duration. Vibrations were of the same duration but of different frequencies (500, 460, 360, and 220 Hz). Pre-pulse inhibition increased with duration of the auditory pre-pulses, as expected. There was significant PPI to some but not all vibrotactile pre-pulses. Multimodal PPI was approximately additive (no significant auditory-by-somatosensory interaction). PPI increased more with age to somatosensory than to auditory pre-pulses. Future studies of multi-modal psychophysics in various mouse mutants could lend support to more mechanistic studies of neural specificity and possibly autism, tinnitus, and PTSD.

Long-term Audiometric Outcomes After Atresiaplasty for Congenital Aural Atresia.

OBJECTIVE: Describe long-term trends and stability of hearing outcomes for patients undergoing primary congenital aural atresia (CAA) repair. STUDY DESIGN: Retrospective chart review. SETTING: Single academic, tertiary referral center. PATIENTS: Children and adults who underwent primary CAA repair between 1980 and 2017. INTERVENTION: CAA repair. MAIN OUTCOME MEASURES: Long-term (> 1 yr) postoperative three-tone (500, 1000, 2000 Hz) air conduction pure-tone average (AC PTA) compared with the immediate (within 90 d of surgery) postoperative audiogram. RESULTS: The mean preoperative AC PTA was 59.6 dB HL. CAA repair improved hearing an average of 30.5 dB, but hearing declined by 8.2 dB over the long-term follow-up period (mean 4.4 yr; range 1-15.7 yr), leaving a final mean improvement of 22.2 dB (final mean AC PTA 37.3 dB HL). Two-thirds (92 of 138 ears) had an AC PTA ≤ 30 dB HL recorded in the first year after surgery. At the last follow-up test, 64% had "stable" hearing defined as no more than a 10 dB decline in AC PTA compared with the immediate postoperative audiogram; 21% had a 10 to 20 dB decline, 8% a 20 to 30 dB decline, and 7% declined > 30 dB. CONCLUSIONS: All patients enjoyed improvement in AC PTA after surgery (preoperative minus the best postoperative PTA, mean = 34 dB, range = 3.3-52 dB). Hearing declined by an average 8.2 dB over the long-term leaving a final average AC PTA of 37.4 dB HL. Sixty-four percent of patients exhibited stable (< 10 dB loss) hearing over time; 36% lost 10 dB or more over the long-term follow-up period. Hearing results typically stabilize over time with most of the change occurring in the first 3 years after CAA repair. Bone conduction thresholds remained stable over the study period.

Quantification of Head Acceleration during Vestibular Rehabilitation Exercises.

PURPOSE: Vestibular rehabilitation exercises have been proven to reduce symptoms and diminish the risk of falls in those with dizziness and balance impairments. The first purpose of this study is to investigate a new method of measuring head movements during habituation vestibular rehabilitation exercises. The second is to explore the relationship between head acceleration measurements during select traditional vestibular rehabilitation exercises and the variables of age, dizziness, and poor balance confidence. RESEARCH DESIGN: A descriptive, cross-sectional study, in a university setting. STUDY SAMPLE: Fifty-two participants, ranging in age from 20 to 96 yr. All were volunteers, with the majority (34) reporting no history of dizziness or balance confidence. DATA COLLECTION: Head accelerations were calculated from linear and angular displacements as measured by magnetometry. RESULTS: Head accelerations decreased with increasing age, dizziness, and low balance confidence during four habituation exercises. CONCLUSIONS: Head acceleration varies as a function of age, dizziness, and low balance confidence during head movement-based vestibular and balance rehabilitation therapy (habituation) exercises. The magnetometry measurement method used could be applied across the course of treatment to establish predictive measures based on change in acceleration over time. More diverse participant sampling is needed to create normative data.

Emergence of Binaural Summation After Surgical Correction of Unilateral Congenital Aural Atresia.

OBJECTIVE: To investigate the emergence of binaural summation in patients with unilateral congenital aural atresia undergoing surgical correction. STUDY DESIGN: Preoperative and postoperative audiometric testing in a prospective cohort of 10 patients with unilateral congenital aural atresia. SETTING: University-based tertiary care center. PATIENTS: Ten patients (ages 6-53) with an average 69 dB (±9 dB sd) unilateral conductive hearing loss, normal hearing in the nonatretic ear, and normal bone conduction in the atretic ear. INTERVENTIONS: Pre- and postoperative hearing in noise test in quiet and in noise. MAIN OUTCOME MEASURES: Levels of sentences presented from a single central speaker were adaptively varied to determine a speech reception threshold (SRT), first in quiet and then with simultaneous multitalker babble at 65 dB SPL from the same speaker. RESULTS: Preoperative SRT was worse than normal controls in both quiet (p = 0.001) and in noise (p = 0.05), as expected. Postoperative SRT in quiet improved 3.5 dB (marginally significant with one-tailed p value of 0.05); thresholds in noise improved an insignificant 0.8 dB (one-tailed p = 0.2). Converting results to dB-worse-than normal, atresia patients did better in noise (relative to normal) than in quiet (p = 0.008). CONCLUSION: The expected summation effect (3 dB) occurs after atresia surgery in quiet but not in noise. Relative to normal, these patients performed better in noise than quiet, perhaps because these patients develop skills attending to threshold-level speech in noise during their years without binaural benefit.

The effects of Eph-ephrin mutations on pre-pulse inhibition in mice.

Eph-ephrin signaling is known to be important in directing topographic projections in the afferent auditory pathway, including connections to various subdivisions of the inferior colliculus (IC). The acoustic startle-response (ASR) is a reliable reflexive behavioral response in mammals elicited by an unexpected intense acoustic startle-eliciting stimulus (ES). It is mediated by a sub-cortical pathway that includes the IC. The ASR amplitude can be measured with an accelerometer under the subject and can be decreased in amplitude by presenting a less intense, non-startling stimulus 5-300ms before the ES. This reflexive decrement in ASR is called pre-pulse inhibition (PPI) and indicates that the relatively soft pre-pulse was heard. PPI is a general trait among mammals. Mice have been used recently to study this response and to reveal how genetic mutations affect neural circuits and hence the ASR and PPI. In this experiment, we measured the effect of Eph-ephrin mutations using control mice (C57BL/6J), mice with compromised EphA4 signaling (EphA4(lacZ/+), EphA4(lacZ/lacZ)), and knockout ephrin-B3 mice (ephrin-B3 (+/-, -/-)). Control and EphA4(lacZ/+s)trains showed robust PPI (up to 75% decrement in ASR) to an offset of a 70dB SPL background noise at 50ms before the ES. Ephrin-B3 knockout mice and EphA4 homozygous mutants were only marginally significant in PPI (<25% decrement and <33% decrement, respectively) to the same conditions. This decrement in PPI highlights the importance of ephrin-B3 and EphA4 interactions in ordering auditory behavioral circuits. Thus, different mutations in certain members of the signaling family produce a full range of changes in PPI, from minimal to nearly maximal. This technique can be easily adapted to study other aspects of hearing in a wider range of mutations. Along with ongoing neuroanatomical studies, this allows careful quantification of how the auditory anatomical, physiological and now behavioral phenotype is affected by changes in Eph-ephrin expression and functionality.

Impact of unilateral conductive hearing loss due to aural atresia on academic performance in children.

OBJECTIVES/HYPOTHESIS: This study evaluates the effect of unilateral conductive hearing loss secondary to aural atresia on elementary school children's academic performance. STUDY DESIGN: Case control survey and review of audiometric data. METHODS: One hundred thirty-two surveys were mailed to families of children with aural atresia, and 48 surveys were sent to families of children with unilateral sensorineural hearing loss (SNHL) to identify rates of grade retention, use of any resource, and behavioral problems. Audiometric data of the cohort were tabulated. RESULTS: Of the 40 atresia patients, none repeated a grade, but 65% needed some resources: 12.5% currently use a hearing aid, 32.5% use(d) a frequency-modulated system in school, 47.5% had an Individualized Education Plan, and 45% utilized speech therapy. Compared to the unilateral SNHL group and a cohort of children with unilateral SNHL in an earlier study, children with unilateral atresia were less likely to repeat a grade. Children in both unilateral atresia and SNHL groups were more likely to utilize some resource in the academic setting compared to the unilateral SNHL children in the prior study. CONCLUSIONS: Unilateral conductive hearing loss due to aural atresia has an impact on academic performance in children, although not as profound when compared to children with unilateral SNHL. The majority of these children with unilateral atresia utilize resources in the school setting. Parents, educators, and health care professionals should be aware of the impact of unilateral conductive hearing loss and offer appropriate habilitative services.

Does preoperative hearing predict postoperative hearing in patients undergoing primary aural atresia repair?

OBJECTIVE: The purpose of this study is to explore the correlation between preoperative hearing and early postoperative hearing results in patients undergoing primary aural atresia repair. STUDY DESIGN: Retrospective review of 125 patients. SETTING: Academic tertiary referral center. PATIENTS: One hundred twenty-five patients (5-67 yr old) undergoing 133 primary aural atresia surgeries were included. MAIN OUTCOME MEASURE(S): Spearman correlation coefficients were calculated between preoperative and postoperative (mean, 7.5 wk; range, 3-40 wk after surgery) hearing outcome measures including 3-tone pure-tone average (PTA), speech reception threshold (SRT), speech discrimination scores (SDS), air-bone gap (ABG), change in ABG (ΔABG), and between preoperative SRT and Jahrsdoerfer score. RESULTS: Preoperative PTA, SRT, SDS, and ABG correlated strongly with their respective postoperative values (correlation coefficients rho of 0.356 [p < 0.01], 0.199 [p < 0.05], 0.480 [p < 0.01], and 0.223 [p < 0.05], respectively). Preoperative PTA (0.407; p < 0.01), SRT (0.348; p < 0.01), SDS (-0.247; p < 0.01), and ABG (0.514; p < 0.01) also were correlated with ΔABG. When postoperative results were dichotomized to either normal (SRT, <30dB HL) or abnormal (SRT, ≥30dB HL), preoperative SRT was found to be a positive predictor of normal postoperative hearing (p = 0.05). Probability of normal postoperative hearing was 66% when preoperative SRT was 50 dB HL or lower and 40% when greater than 60 dB HL. Preoperative hearing (SRT) also trended toward a correlation with Jahrsdoerfer score (-0.168 [p = 0.058]). CONCLUSION: Among patients undergoing primary atresia repair, better preoperative hearing strongly predicts better postoperative hearing and correlates with ear anatomy. Preoperative hearing status should be factored when counseling atresia patients on hearing rehabilitation options.

Training children with ADHD to minimize impulsivity in auditory contralateral masking.

OBJECTIVE: Impulsivity and distractibility are among the important symptoms of attention deficit hyperactivity disorder (ADHD). In this study, impulsivity is operationally measured using false-alarm rates in an auditory, contralateral-masking task. Intensive auditory training was attempted to decrease false alarm rates. METHODS: In contralateral masking there is a distracting noise in one ear on every trial and a threshold-level tone in the other ear on half of those trials. Participants indicated whether the tone was present or not and received immediate feedback. The intensity of the masked tone was adaptively varied to track threshold. False alarms are the error of commission, saying that a stimulus is present when it is not. Seven school-aged children with ADHD (ages 10-16) and four adults without ADHD were trained on this task for 900 trials per day over four consecutive days. RESULTS: False alarms from the children with ADHD decreased over the four days of training, beginning at the high level and ending at the low level expected from previous studies. There was no generalization to a different masking task. Results from the four adults were unexpected: soon after the training began they behaved no differently than the children with ADHD. CONCLUSION: Children with ADHD can be trained to become less impulsive in an auditory detection task.

Constructed charts of vaccination strategies.

Various vaccination rates are mathematically modeled as if they simply spread from area to next nearest area across a 'constructed landscape' of developing countries. A technique that had previously been used to model the spread of diseases effectively models the spread of disease prevention. Multidimensional scaling successfully summarizes complex patterns in vaccination rates in developing countries as a 'constructed chart' from 'functional distances'. Countries that have similar vaccination rates are close together in this constructed chart, and countries that have different rates are far apart, regardless of the physical distance between the countries. A statistically significant (p < 0.001) chart was made of seven different vaccination rates (diphtheria, polio, measles in adults, measles in infants, tuberculosis in adults, tuberculosis in infants, and total percentage of routine epidemic vaccines financed by government) in 49 developing countries (from Belarus, Belize and Benin to Vietnam, Yemen and Zimbabwe).

Understanding speech in noise after correction of congenital unilateral aural atresia: effects of age in the emergence of binaural squelch but not in use of head-shadow.

OBJECTIVE: Unilateral hearing loss causes difficulty hearing in noise (the "cocktail party effect") due to absence of redundancy, head-shadow, and binaural squelch. This study explores the emergence of the head-shadow and binaural squelch effects in children with unilateral congenital aural atresia undergoing surgery to correct their hearing deficit. Adding patients and data from a similar study previously published, we also evaluate covariates such as the age of the patient, surgical outcome, and complexity of the task that might predict the extent of binaural benefit--patients' ability to "use" their new ear--when understanding speech in noise. METHODS: Patients with unilateral congenital aural atresia were tested for their ability to understand speech in noise before and again 1 month after surgery to repair their atresia. In a sound-attenuating booth participants faced a speaker that produced speech signals with noise 90 degrees to the side of the normal (non-atretic) ear and again to the side of the atretic ear. The Hearing in Noise Test (HINT for adults or HINT-C for children) was used to estimate the patients' speech reception thresholds. The speech-in-noise test (SPIN) or the Pediatric Speech Intelligibility (PSI) Test was used in the previous study. RESULTS: There was consistent improvement, averaging 5dB regardless of age, in the ability to take advantage of head-shadow in understanding speech with noise to the side of the non-atretic (normal) ear. There was, in contrast, a strong negative linear effect of age (r(2)=.78, selecting patients over 8 years) in the emergence of binaural squelch to understand speech with noise to the side of the atretic ear. In patients over 8 years, this trend replicated over different studies and different tests. Children less than 8 years, however, showed less improvement in the HINT-C than in the PSI after surgery with noise toward their atretic ear (effect size=3). No binaural result was correlated with degree of hearing improvement after surgery. CONCLUSIONS: All patients are able to take advantage of a favorable signal-to-noise ratio in their newly opened ear; that is with noise toward the side of the normal ear (but this physical, bilateral, head-shadow effect need not involve true central binaural processing). With noise toward the atretic ear, the emergence of binaural squelch replicates between two studies for all but the youngest patients. Approximately 2dB of binaural gain is lost for each decade that surgery is delayed, and zero (or poorer) binaural benefit is predicted after 38 years of age. Older adults do more poorly, possibly secondary to their long period of auditory deprivation. At the youngest ages, however, binaural results are different in open- and closed-set speech tests; the more complex hearing tasks may involve a greater cognitive load. Other cognitive abilities (late evoked potentials, grey matter in auditory cortex, and multitasking) show similar effects of age, peaking at the same late-teen/young-adult period. Longer follow-up is likely critical for the understanding of these data. Getting a new ear may be--like multitasking--challenging for the youngest and oldest subjects.

Efficacy of neck dissection: are surgical volumes important?

UNLABELLED: OBJECTIVES/HYPHOTHESIS: Surgical volumes have been shown in many fields to reflect expertise and to be associated with improved clinical outcomes. We sought to test similar hypotheses that neck dissection is a volume-sensitive procedure wherein the number of lymph nodes harvested and clinical outcomes are correlated with the number of neck dissections performed. METHODS: We conducted a retrospective analysis of 375 neck dissections. The number of nodes harvested was examined by multiple linear regression before and after mathematical correction for pathologists' variation over time. The prior experiences of the surgeons were also averaged, depending on whether there was regional recurrence after at least 9 months of follow-up. RESULTS: More nodes were found by the pathologists over time, with 2.1 more nodes being found on average for each successive year (P < .001). After correcting for this effect of time, there remained a significant relationship between surgeons' experience and number of nodes harvested (P < .003). Additionally, cases that recurred were operated by less-experienced surgeons (P = .02). CONCLUSIONS: We have demonstrated that there is a "learning curve" for neck dissection. Our most experienced surgeon harvested on average 11 more nodes than similar specimens submitted by the group of inexperienced surgeons. The effect of experience remains significant even without adjusting for time (P < .001). Surgical experience also affects clinical outcome months after the dissection. This retrospective review supports surgical volume as an indicator of expertise in neck dissection that could be used to assess trainees' progress and for quality assurance in large head and neck units. Laryngoscope, 2009.

Do former preterm infants remember and respond to neonatal intensive care unit noise?

BACKGROUND: Previous studies have shown that 4-month-old infants have a decrease in heart rate, a component of the orienting reflex, in response to interesting auditory stimuli and an increase in heart rate to aversive auditory stimuli. OBJECTIVE: To compare the heart rate responses of former preterm and term infants at 4-5 months corrected age to a recording of NICU noises. METHODS: 13 former preterm infants and 17 full-term infants were presented NICU noise and another noise of similar level and frequency content in random order. Heart rate 10s prior to the stimulus and for 20s during the stimulus was analyzed. Group differences in second by second heart rate changes in response to the two noise stimuli were compared by analysis of covariance. RESULTS: Both the preterm and term newborns responded similarly to the NICU noise and the control noise. The preterm infants did not alter their heart rate in response to either stimulus. In contrast, the term infants displayed an orienting response to the second stimulus presented regardless of whether it was the NICU or control noise. CONCLUSIONS: Former preterm infants at 4-5 months corrected age have reduced responsiveness to auditory stimulation in comparison to 4- to 5-month-old term infants. Furthermore, they did not respond to the NICU noise as an aversive stimulus.

The effect of lead on the avian auditory brainstem.

Lead (Pb) continues to be a significant environmental toxin and remains an integral part of many industrial processes, hobbies, and tobacco smoke. Pb has been shown to be a potent toxin to the CNS and low levels of Pb (below the CDC established toxic blood level of 10 microg/dl) have been correlated with decreases in the IQ of children. Pb exposure is a risk factor for dyslexia, and significantly, dyslexics have deficits in auditory temporal processing, including backward masking and amplitude modulation detection. Importantly, Pb-exposed children have been found to be deficient in various aspects of auditory temporal processing, including backward masking. Auditory temporal information is vital for appropriate speech detection and it is not known where within the auditory axis temporal processing takes place, nor is it understood how Pb exposure modifies the cells of the auditory system. To address these questions, we have developed an animal model of auditory temporal processing using chickens and have established that Pb exposure during development results in deficits in backward masking in avians. The current study was undertaken to identify the cellular changes induced by Pb exposure in the auditory brainstem of chickens that are likely anatomical correlates of the observed deficits in backward masking. We found Pb exposure had no effect on neuron number or glial cells within the auditory brainstem. However, Pb exposure does result in significant decreases in the amount of the medium weight neurofilament protein (NFM) as well as decreased NFM phosphorylation within the axons connecting auditory nuclei in the avian brainstem. Because the amount of neurofilament can affect the conduction velocities of axons, these results may provide an anatomical link between Pb exposure, auditory temporal processing deficits, and dyslexia.

Pressed scar tissue for tympanic membrane grafting in revision tympanoplasty.

OBJECTIVE: Compare the efficacy of pressed scar tissue grafts to standard fascia and areolar tissue grafts for use in tympanoplasty. STUDY DESIGN: A retrospective review of a prospective computerized database of tympanoplasty and mastoid surgeries at an academic, tertiary care practice was performed. Search parameters were set to find all patients who underwent tympanoplasty with or without mastoidectomy with use of various grafting materials for repair of tympanic membrane perforation from 1996 to 2002. All ages were included. Patients with cholesteatoma at the time of surgery were excluded. The short-term graft take rate was evaluated at 30 to 90 days to identify any differences in results using the standard fascia and areolar grafts vs. pressed scar tissue grafts. Other parameters that may have an influence on outcome were analyzed including mastoidectomy, infection, perforation size, perforation location, age of patient, primary vs. revision surgery, number of previous surgeries, postauricular vs. transcanal approaches, and medial vs. lateral grafting techniques. Hearing results were analyzed to see whether the use of scar tissue grafts resulted in equivalent outcomes compared to standard graft materials. RESULTS: There were no statistically significant differences in short-term tympanic membrane closure rates in subjects undergoing surgery using standard fascia/areolar tissue grafts and pressed scar tissue grafts. Hearing results were also statistically equivalent regardless of graft material used. The only parameter that was somewhat associated with successful closure of tympanic perforation was use of the postauricular approach compared to the transcanal approach. CONCLUSIONS: Pressed scar tissue grafts are as efficacious as standard fascia and areolar tissue grafts when used to repair tympanic membrane perforations. Pressed scar tissue graft can be used successfully in cases such as revision tympanoplasty when standard tissue grafts are not available or difficult to obtain. EBM RATING: B-3.

Effects of the neonatal intensive care unit on auditory attention and distraction.

A theory is proposed that attention to acoustic signals is important for normal development and varies with background masking sounds. Specifically, the theory states that distractibility increases with decreasing predictability of the acoustic environment and with decreasing age. Literature from premature neonates, normal infants, preadolescent children, children with attention deficit disorders, and adults is reviewed. One conclusion is that an environment perceived by adults as predictable may be distracting for preterm infants. One recommendation for future research is to include measures of background acoustic predictability as independent variables or covariates in developmental studies.

Functional maps of metastases from breast cancers: proof of the principle that multidimensional scaling can summarize disease progression.

The mathematic technique of multidimensional scaling can create "functional maps" of metastases from breast cancer such that positions of organs in these maps are proportional to the probability of metastases. Areas that are likely to share disease are close together in a functional map, even though they may be physically distant, and vice versa. Two functional maps of breast cancers-one of local metastases to axillary levels I to III and another of distant metastases-are statistically significant and clinically meaningful. The maps accurately reflect the clinical data ( r > 0.97, p < 0.01), and so the progression of disease is revealed in simple visual summaries. As an analogy, the metastatic sites are like buoys on a fluid surface, and cancer spreads from a primary tumor like waves emanating from a point of impact on that surface. Metastases are predicted when the waves swamp the buoys. Because breast cancers do not always spread to the next nearest site, these functional maps do not resemble anatomic maps. The maps are a view of the body as "seen" by the tumor. Several well known clinical features are seen in these maps: most local metastases are to axillary level I; upper-inner primaries spread equally to levels II and III; in-transit metastases in the lymph and blood vessels do not follow the pattern of other distant metastases. Future functional maps can expand these summary diagrams to include biologic parameters (gene-expression profiles or endocrine response) and give valuable insights into patterns of recurrence in different populations.