Uncomfortable loudness levels among children and adolescents seeking help for tinnitus and/or hyperacusis

Objective: To assess the prevalence of hyperacusis and severe hyperacusis among children and adolescents seen at an audiology outpatient tinnitus and hyperacusis service.

Design: This was a retrospective study. Hyperacusis was considered as present if the average uncomfortable loudness level (ULL) at 0.25, 0.5, 1, 2, 4 and 8?kHz for the ear with the lower average ULL, which is denoted as ULLmin, was ≤77?dB HL. Severe hyperacusis was considered as present if the ULL was 30?dB HL or less for at least one of the measured frequencies for at least one ear.

Study sample: There were 62 young patients with an average age of 12?years (SD?=?4.1?years, range 4–18?years).

Results: Eighty-five percent of patients had hyperacusis and 17% had severe hyperacusis. On average, ULLs at 8?kHz were 9.3?dB lower than ULLs at 0.25?kHz. For 33% of patients, ULLs were at least 20?dB lower at 8 than at 0.25?kHz.

Conclusions: Among children and adolescents seen at an audiology outpatient clinic for tinnitus and hyperacusis, hyperacusis diagnosed on the basis of ULLs is very prevalent and it is often characterised by lower ULLs at 8 than at 0.25?kHz.     

Vestibular myogenic potentials evoked by air-conducted stimuli at safe acoustic intensity levels retain optimal diagnostic properties for superior canal dehiscence syndrome

Background: Vestibular-evoked myogenic potential (VEMP) is commonly conducted with air-conducted (AC) stimuli whose intensity may exceed the prudential levels of acoustic exposure in susceptible subjects.

Objectives: To determine the diagnostic accuracy of AC VEMP for superior canal dehiscence syndrome (SCDS) at lowered acoustic stimulation levels.

Material and methods: VEMP was tested in 10 SCDS patients and in 10 age/sex matched control subjects. VEMP were recorded on cervical muscles (cVEMP) and extraocular muscles (oVEMP) in response to short AC tone bursts at 500, 1000 and 2000?Hz delivered at 80?dB nHL (103?dB peSPL). Parameters of interest were the response amplitude and the frequency tuning.

Results: VEMP evoked by AC stimuli at safe acoustic stimulation levels did effectively separate SCDS patients from healthy controls. The separation was optimal at all the frequencies tested, however 500?Hz resulted the best VEMP tuning frequency, especially at oVEMP.

Conclusions: Lowering the AC stimulation to the levels compatible with testing of patients susceptible to acoustic exposure didn’t affect the VEMP diagnostic properties for SCDS.

Significance: SCDS may be screened by VEMP even among subjects susceptible for acoustic exposure.     

Prevalence and risk factors for reduced sound tolerance (hyperacusis) in children

Objective: To estimate the prevalence of reduced sound tolerance (hyperacusis) in a UK population of 11-year-old children and examine the association of early life and auditory risk factors with report of hyperacusis. Design: A prospective UK population-based study. Study sample: A total of 7097 eleven-year-old children within the Avon longitudinal study of parents and children (ALSPAC) were asked about sound tolerance; hearing and middle-ear function was measured using audiometry, otoacoustic emissions, and tympanometry. Information on neonatal risk factors and socioeconomic factors were obtained through parental questionnaires. Results: 3.7% (95% CI 3.25, 4.14) children reported hyperacusis. Hyperacusis report was less likely in females (adj OR 0.64, 95% CI 0.49, 0.85), and was more likely with higher maternal education level (adj OR 1.72, 95% CI 1.08, 2.72) and with readmission to hospital in first four weeks (adj OR 1.98, 95% CI 1.20, 3.25). Report of hyperacusis was associated with larger amplitude otoacoustic emissions but with no other auditory factors. Conclusions: The prevalence of hyperacusis in the population of 11-year-old UK children is estimated to be 3.7%. It is more common in boys.     

Mild iron deficiency anaemia during pregnancy and lactation in guinea pigs alters amplitudes and auditory nerve velocity,but not brainstem transmission times in the offspring's auditory brainstem response

Objectives

It is well known that postnatal/early childhood iron deficiency (ID) anaemia (IDA) adversely affects infants' cognitive development and neurophysiology. However, the effects of IDA during gestation and lactation on the offspring are largely unknown. To address this health issue, the impact of mild IDA during gestation and lactation on the offsprings' neural maturation was studied in the guinea pig, using auditory brainstem responses (ABRs) latencies and amplitudes.

Methods

Female guinea pigs (n = 10/group) were fed an iron sufficient (ISD) or deficient diet (IDD) (144 and 11.7 mg iron/kg) during the gestation and lactation periods. From postnatal day (PNd) 9 onward, the ISD was given to both groups of weaned offspring. The offsprings' ABRs were collected on PNd24 using a broad range of stimulus intensities in response to 2, 4, 8, 16, and 32 kHz tone pips.

Results

Although the IDA siblings (n = 8) did not differ in brainstem transmission times (BTTs) compared to the IS siblings (n = 8), they showed significant delayed peak I latency at 100 and 80 dB, respectively. Additionally, significantly higher ABR wave amplitudes were observed in the IDA female offspring between 35 and 50 dB (4 kHz), a phenomenon suggestive of a neural hyperactivity (hyperacusis).

Discussion

In support to our previous findings, the present results indicate that a mild IDA during gestation and lactation can have detrimental effects on early development of the offsprings' hearing and nervous systems, particularly on neural synchrony and auditory nerve conduction velocity, but not on BTT.     

听觉耐受下降与耳鸣

听觉耐受下降(decreased sound tolerance)是指对声音的容忍度降低,或指对声音的敏感性增强,包括听觉过敏,厌声症,恐声症〔1〕。耳鸣是指在周围环境中无相应声源或电刺激存在的情况下,患者自觉耳内或颅内有声音的一种主观感觉;常伴或     

Tinnitus and hyperacusis in children: clinic reports and basic research

Objective Tinnitus and hyperacusis are subjective symptoms which can be reported by people of any age. Although tinnitus and hyperacusis can have a negative effect on child development, these symptoms are commonly overlooked by their parents and clinicians. In this paper, we review clinical reports on tinnitus and hyperacusis in children and basic scientific studies on these disorders in order to provide updates of these disorders in the pediatric population. Recent studies have found that tinnitus and hyperacusis are not uncommon in children, especially in those with conductive and sensorineural hearing loss. The parents and clinicians should pay attention when children show abnormal behaviors and especially when they develop hearing loss. Since there is no objective measurement for tinnitus and hyperacusis, the diagnosis in children can be challenging. Tinnitus and hyperacusis are also common in Williams syndrome and autism but the mechanisms are still not clear. High doses of salicylate and noise exposure can induce tinnitus. Animal studies have determined lack of inhibition in the auditory cortex and the inferior colliculus may be critical for tinnitus and hyperacusis generation. The non-classic auditory system may also be involved in the awareness and tolerance of tinnitus and hyperacusis.     

颞骨内面神经麻痹的听觉过敏和镫骨肌反射的相关性

对150例面瘫进行ART和听觉过敏的相关性探讨,ART与听觉过敏相关例39%,矛盾例61%。ART、听觉过敏与NET失神经程度无相关性。并通过ABR、SISI、ABLB等进一步探讨了听觉过敏的成因。     

FIRING PROPERTY OF INFERIOR COLLICULUS NEURONS AFFECTED BY FMR1 GENE MUTATION

Fragile X syndrome is the most common form of inherited mental retardation affecting up to 1 in 4000 individuals. The syn- drome is induced by a mutation in the FMR1 gene, causing a deficiency in its gene by-product FMRP. Impairment in the nor- mal functioning of FMRP leads to learning and memory deficits and heightened sensitivity to sensory stimuli, including sound （hyperacusis）. The molecular basis of fragile X syndrome is thoroughly understood; however, the neural mechanisms underly- ing hyperacusis have not yet been determined. As the inferior colliculus （IC） is the principal midbrain nucleus of the auditory pathway, the current study addresses the questions underlying the neural mechanism of hyperacusis within the IC of fragile X mice. Acute experiments were performed in which electrophysiological recordings of the IC in FMR1-KO and WT mice were measured. Results showed that Q-values for WT were significantly larger than that of FMR-1 KO mice, indicating that WT mice exhibit sharper tuning curves than FMR1-KO mice. We also found the ratio of the monotonic neurons in the KO mice was much higher than the WT mice. These results suggest that lack of FMRP in the auditory system affects the developmental maturation and function of structures within the auditory pathway, and in this case specifically the IC. The dysfunction ob- served within the auditory neural pathway and in particular the IC may be related to the increased susceptibility to sound as seen in individuals with fragile X syndrome. Our study may help on understanding the mechanisms of the fragile X syndrome and hyperacusis.     

Temporary Suppression of Tinnitus by Modulated Sounds

Despite high prevalence of tinnitus and its impact on quality life, there is no cure for tinnitus at present. Here, we report an effective means to temporarily suppress tinnitus by amplitude- and frequency-modulated tones. We systematically explored the interaction between subjective tinnitus and 17 external sounds in 20 chronic tinnitus sufferers. The external sounds included traditionally used unmodulated stimuli such as pure tones and white noise and dynamically modulated stimuli known to produce sustained neural synchrony in the central auditory pathway. All external sounds were presented in a random order to all subjects and at a loudness level that was just below tinnitus loudness. We found some tinnitus suppression in terms of reduced loudness by at least one of the 17 stimuli in 90% of the subjects, with the greatest suppression by amplitude-modulated tones with carrier frequencies near the tinnitus pitch for tinnitus sufferers with relatively normal loudness growth. Our results suggest that, in addition to a traditional masking approach using unmodulated pure tones and white noise, modulated sounds should be used for tinnitus suppression because they may be more effective in reducing hyperactive neural activities associated with tinnitus. The long-term effects of the modulated sounds on tinnitus and the underlying mechanisms remain to be investigated.