The effect of environmental noise isolation on bronchiolitis severity in hospitalised children.

AIM: Bronchiolitis is an infectious disease, with no effective treatment. Music and Mozart's works specifically are known to have a positive effect on physiological parameters, while noise is considered harmful. We aim to evaluate the short-term effect of environmental noise detachment and/or music listening on the course of bronchiolitis in hospitalised children. METHODS: This is a prospective, double-blinded randomised controlled trial. Patients were divided into three intervention groups: 1-Mozart's Sonata, 2-instrumental music, 3-silence. Music was heard via media players and soundproof headphones. Disease severity was evaluated before and after intervention using the Modified Tal score. RESULTS: Seventy music sessions were included in the analysis (Mozart n = 23, instrumental n = 22, silence n = 25). A one-point drop in the average bronchiolitis severity score was observed in all three groups from 7.1 (CI 95%, 5 to 9.2) to 6.1 (CI 95%, 4.3 to 7.9), p < 0.001. No significant difference was found between the three groups with respect to change in the severity score before and after the intervention. CONCLUSION: Isolation from disturbing sounds heard in paediatric departments could be considered a simple non-invasive intervention in children hospitalised with bronchiolitis. Further studies are warranted to evaluate long-term effects of this intervention and the specific effect of music.

Predicting hearing thresholds in occupational noise-induced hearing loss by auditory steady state responses.

OBJECTIVES: Currently available behavioral tools for the assessment of noise-induced hearing loss (NIHL) depend on the reliable cooperation of the subject. Furthermore, in workers' compensation cases, there is considerable financial gain to be had from exaggerating symptoms, such that accurate assessment of true hearing threshold levels is essential. An alternative objective physiologic tool for assessing NIHL is the auditory steady state response (ASSR) test, which combines frequency specificity with a high level of auditory stimulation, making it applicable for the evaluation of subjects with a moderate to severe deficit. The primary aim of the study was to assess the value of the multifrequency ASSR test in predicting the behavioral warble-tone audiogram in a large sample of young subjects with NIHL of varying severity or with normal hearing. The secondary goal was to assess suprathreshold ASSR growth functions in these two groups. DESIGN: The study group included 157 subjects regularly exposed to high levels of occupational noise, who attended a university-associated audiological clinic for evaluation of NIHL from 2009 through 2011. All underwent a behavioral audiogram, and on the basis of the findings, were divided into those with NIHL (108 subjects, 216 ears) or normal hearing (49 subjects, 98 ears). The accuracy of the ASSR threshold estimations for frequencies of 500, 1000, 2000, and 4000 Hz was compared between groups, and the specificity and sensitivity of the ASSR test in differentiating ears with or without NIHL was calculated using receiver operating characteristic analysis. Linear regression analysis was used to formulate an equation to predict the behavioral warble-tone audiogram at each test frequency using ASSR thresholds. Multifrequency ASSR amplitude growth as a function of stimulus intensity was compared between the NIHL and normal-hearing groups for 1000 Hz and 4000 Hz carrier frequencies. RESULTS: In the subjects with NIHL, ASSR thresholds to various frequencies were significantly and highly correlated with the behavioral warble-tone thresholds; Pearson correlation coefficients ranged from 0.6 to 0.8 over the four frequencies tested. Differences between thresholds ranged from 10 to 13 dB. The configuration of the ASSR waveforms closely approximated the behavioral audiogram. The sensitivity for screening hearing thresholds was 92%; by frequency, sensitivity ranged between 92.7 and 98.4%, but specificity was lower, especially at the low frequencies. ASSR accurately predicted moderate and severe NIHL. The mean ASSR growth amplitude to increasing stimulus level for 1000 and 4000 Hz was significantly steeper in the NIHL than in the normal-hearing group, with no significant difference between frequencies. CONCLUSIONS: The ASSR test has a high sensitivity to detect moderate to severe hearing loss in subjects with NIHL. Its use can facilitate the early identification of noise-exposed workers with NIHL. It may also serve an important medico-legal function in cases of workers' compensation. The ASSR test is not, by itself, an appropriate tool for hearing screening in the general population.

Animal model of cochlear third window in the scala vestibuli or scala tympani.

HYPOTHESIS: The auditory impact of a cochlear third window differs by its location in the scala vestibuli or scala tympani. BACKGROUND: Pathologic third window has been investigated primarily in the vestibular apparatus of animals and humans. Dehiscence of the superior semicircular canal is the clinical model. METHODS: Fat sand rats (n = 11) have a unique inner-ear anatomy that allows easy surgical access. A window was drilled in the bony labyrinth over the scala vestibuli in 1 group (12 ears) and over the scala tympani in another (7 ears) while preserving the membranous labyrinth. Auditory brain stem responses to high- and low-frequency stimuli delivered by air and bone conduction were recorded before and after the procedure. RESULTS: Scala vestibuli group: preoperative air-conduction thresholds to clicks and tone-bursts averaged 8.3 and 9.6 dB, respectively, and bone-conduction thresholds, 4.6 and 3.3 dB, respectively; after fenestration, air-conduction thresholds averaged 40.4 and 41.8 dB, respectively, and bone-conduction thresholds, -1 and 5.6 dB, respectively. Scala tympani group: preoperative air-conduction thresholds to clicks and tone-bursts averaged 8.6 dB each, and bone-conduction thresholds, 7.9 dB and 7.1 dB, respectively; after fenestration, air-conduction thresholds averaged 11.4 and 9.3 dB, respectively, and bone-conduction thresholds, 9.3 and 4.2 dB, respectively. The changes in air- (p = 0.0001) and bone-conduction (p = 0.04) thresholds were statistically significant only in the scala vestibuli group. CONCLUSION: The presence of a cochlear third window over the scala vestibuli, but not over the scala tympani, causes a significant increase in air-conduction auditory thresholds. These results agree with the theoretic model and clinical findings and contribute to our understanding of vestibular dehiscence.

Hyperactive auditory efferent system and lack of acoustic reflexes in Williams syndrome.

The auditory efferent system and acoustic reflexes have been investigated in patients with Williams syndrome (WS). Twenty-one patients aged 6-26 years with a genetically confirmed diagnosis of WS and with reported hyperacusis were compared with 21 normally developing age-matched subjects. The medial olivocochlear (MOC) efferent system was tested by stimulation of the contralateral ear with increasing levels of white noise, while recording transient evoked otoacoustic emissions (TEOAE) in the ipsilateral ear. The suppression effect on the amplitudes of the TEOAE was computed for each contralateral stimulus level. This measure reflects the strength of the MOC efferent system. In addition, the thresholds of ipsilateral and contralateral acoustic reflexes in response to 1, 2 and 4 kHz tones as well as to broadband stimuli were also recorded. Results showed that patients with WS had a significantly higher suppression effect of the MOC reflex on TEOAE. Ipsilateral and contralateral acoustic reflexes to tonal and broadband stimuli presented at maximum stimulus intensities were absent in 62-86% of the patients with WS. In the remainder, acoustic reflexes were elicited at lower auditory sensation thresholds than in controls. Hyperexcitability of the MOC efferent system coupled with absence of acoustic reflexes may contribute to the hyperacusis in WS and the consequent high-tone hearing loss induced by environmental noise. Both measures can be used for objective detection and thus, intervention of hyperacusis in the early stages of life.