Tinnitus Assessment and Management: A Survey of Practicing Audiologists in the United States and Canada.

BACKGROUND: Tinnitus is a prevalent auditory disorder that can become severely debilitating. Despite decades of investigation, there remains no conclusive cure for tinnitus. Clinical practice guidelines (CPGs) are available for assessing and managing tinnitus. Even though such guidelines have been available for several years, the degree that audiologists adhere to them has remained unexplored. PURPOSE OF STUDY: To determine what clinical practices are commonly used by audiologists in the assessment and management of the patient population with tinnitus, we administered an online survey to audiologists practicing in the United States and Canada. RESULTS: Among the audiologists that completed the survey and were included in the final analysis (n = 61), 70% were from the United States and 30% were from Canada. The audiologists represented a wide range of clinical experience (1-35 years). On average, those who completed the survey were relatively confident in their ability to assess and manage tinnitus patients indicated by a 0 to 100 Likert scale, with 0 representing no confidence (mean 72.5, ± 21.5 standard deviation). The most commonly reported tinnitus assessment tools were pure tone audiogram (0.25-8 kHz), administration of standardized questionnaires, and tinnitus pitch and loudness matching. Approximately half (55%) of audiologists indicated they include otoacoustic emissions, while less audiologists (<40%) reported measuring high-frequency thresholds, minimum masking levels, or loudness discomfort levels. The most common recommendation for tinnitus patients was amplification (87%), followed by counseling (80%) and sound therapy (79%). CONCLUSION: Few audiologists administer a truly comprehensive tinnitus assessment and ∼20% indicated not recommending counseling or sound therapy to manage tinnitus. The results are discussed in the context of what is explicitly indicated in published CPGs, professional organization recommendations, and recent findings of peer-reviewed literature.

Evaluating the benefit of hearing aids with motion-based beamformer adaptation in a real-world setup.

OBJECTIVE: Conventional directional hearing aid microphone technology may obstruct listening intentions when the talker and listener walk side by side. The purpose of the current study was to evaluate hearing aids that use a motion sensor to address listening needs during walking. DESIGN: Each participant completed two walks in randomised order, one walk with each of two hearing aid programs: (1) conventional beamformer adaptation that activated an adaptive, multiband beamformer in loud environments and (2) motion-based beamformer adaptation that activated a pinna-mimicking microphone setting when walking was detected. Participants walked along a pre-defined track and completed tasks assessing speech understanding and environmental awareness. STUDY SAMPLE: Participants were 22 older adults with moderate-to-severe hearing loss and experience using hearing aids. RESULTS: More participants preferred the motion-based than conventional beamformer adaptation for speech understanding, environmental awareness, overall listening, and sound quality (p < 0.05). Measures of speech understanding (p < 0.01) and localisation of sound stimuli (p < 0.05) were significantly better with motion-based than conventional beamformer adaptation. CONCLUSIONS: The results suggest that hearing aid users can benefit from beamforming that uses motion sensor input to adapt the signal processing according to the user's activity. The real-world setup of this study had limitations.

Infant Cortical Auditory Evoked Potentials to Lateralized Noise Shifts Produced by Changes in Interaural Time Difference.

OBJECTIVES: Newborns reliably orient to sound location soon after birth; by age 1 month this orienting disappears until after age 4 months. It has been suggested that orienting by the newborn reflects subcortical-mediated reflexes, which are suppressed by age 1 month; reappearance of orienting then occurs after age 4 months with maturation of cortical mechanisms of sound localization. In the present study, we assess auditory lateralization in young infants (and adults) by recording slow cortical auditory evoked potentials to lateralization shifts in dichotic noise produced by changes in interaural time difference (ITD). DESIGN: Fifteen normal infants aged under 4 months (mean = 10.7 weeks) had cortical auditory evoked potentials assessed in response to (1) diotic "onset" noise bursts (0 msec ITD) and (2) shifts in continuous lateralized noise (75 dB SPL) produced by ITD shifts of 0.5, 0.8, 1, 2, 4, and 8 msec. Shifts alternated between ears occurred every 2 sec. Stimuli were presented using insert earphones; infants slept during recordings. For comparison, similar recordings were obtained in 11 normal-hearing, awake, adults. Additionally, "control" recordings to the ITD-shift stimuli presented to only one ear were obtained in the adults. RESULTS: Similar to previous research, adults showed clear N1-P2 responses to the lateralization shifts (ITD 0.5 to 2.0 msec). Responses decreased for longer ITD shifts, with no adult responses to the 8-msec ITD shift. N1 latencies to ITD-shift stimuli were 28 to 34 msec longer than to the onset stimuli. No responses were seen in the control conditions when ITD-shift stimuli were presented to only one ear (confirming the binaural nature of the ITD-shift responses). All infants showed P2 responses to one or more of the ITD-shift stimuli up to ±1 msec; compared with adults, infants showed larger amplitude decreases and fewer responses to longer ITD-shift stimuli. As was seen with the adult responses, infant response (P2) latencies to ITD shifts were longer compared with their responses to the onset stimuli; however, these increases, 32 to 78 msec, were significantly longer than those seen in the adults. CONCLUSIONS: Young infants (even as young as 5 weeks) show clear evidence of auditory cortical responsivity to lateralization shifts produced by changes in the ITD of continuous noise, indicating that they have the capacity to process binaural ITD timing cues well before the age of 4 months. Further research is required to determine whether the larger latency increase in infants for ITD-shift stimuli (relative to the onset stimuli) and the greater effect of longer ITD shifts on response presence and amplitude in infants reflects immaturity of lateralization processing and/or reduced responses recorded during sleep. Slow cortical auditory evoked potentials elicited to lateralization shifts in dichotic noise provide a method to investigate binaural hearing processes in young children with normal or impaired hearing.

Multiple-ASSR Interactions in Adults with Sensorineural Hearing Loss.

The multiple auditory steady-state response (multiple-ASSR) technique, where thresholds for up to 8 frequencies (4 in each ear) are obtained simultaneously, is currently of great interest for audiometric assessment of infants. Although threshold estimates using the multiple-ASSR appear to be reasonably accurate, it is not currently known whether it is more efficient to use multiple stimuli or single stimuli when testing individuals with sensorineural hearing loss (SNHL). The current study investigated the effect of single versus multiple simultaneous stimuli on the 80- and 40-Hz ASSRs in adults with normal hearing or SNHL. Results showed significant interactions (i.e., decreased amplitudes) for both ASSRs going from single to multiple stimuli in one ear. Going from multiple one ear to multiple two ears did not further reduce the amplitude of the 80-Hz ASSR. At the 40-Hz rate, however, there was a further amplitude decrease going from one-ear multiple to two-ear multiple stimuli. Importantly, these interactions did not differ between the normal-hearing and SNHL groups. Although supportive of the multiple-ASSR technique, there are likely situations where it is more efficient to use single stimuli. Future studies are required to assess these interactions in infants with varying degrees and configurations of hearing loss.

Multiple auditory steady state response thresholds to bone conduction stimuli in adults with normal and elevated thresholds.

OBJECTIVE: Auditory steady state responses (ASSRs) to multiple air conduction (AC) stimuli modulated at ∼80 Hz have been shown to provide reasonable estimates of the behavioral audiogram. To distinguish the type of hearing loss (i.e., conductive, sensorineural, or mixed), bone conduction (BC) results are necessary. There are few BC-ASSR data, especially for individuals with hearing loss. The present studies aimed to (1) determine multiple ASSR thresholds to BC stimuli in adults with normal hearing, masker-simulated hearing loss, and sensorineural hearing loss (SNHL) and (2) determine how well BC-ASSR distinguishes normal versus elevated thresholds to BC stimuli in adults with normal hearing or SNHL. DESIGN: Multiple ASSR and behavioral thresholds for BC stimuli were determined in two studies. Study A assessed 16 normal-hearing adults with relatively flat threshold elevations produced by 50, 60, and 70 dB SPL AC masking noise, as well as no masking. Study B assessed 10 adults with normal hearing and 40 adults with SNHL. In both studies, the multiple (500 to 4000 Hz) ASSR stimuli were modulated between 77 and 101 Hz and varied in intensity from 0 to 50 dB HL in 10-dB steps. Stimuli were presented using a B71 bone oscillator held on the temporal bone by an elastic band while participants relaxed or slept. RESULTS: Study A: Correlations (r) between behavioral and ASSR thresholds for all conditions combined were 0.77, 0.87, 0.90, and 0.87 for 500, 1000, 2000, and 4000 Hz, respectively. ASSR minus behavioral threshold difference scores for all frequencies combined for the no-masker, 50, 60, and 70 dB SPL masker conditions were 14.3 ± 9.2, 12.1 ± 10.4, 12.7 ± 7.7, and 11.4 ± 8.1 dB, respectively. Study B: The difference scores for 500, 1000, 2000, and 4000 Hz were, on average, 15.7 ± 12.3, 10.3 ± 10.7, 9.7 ± 10.3, and 5.7 ± 7.9 dB, respectively, with correlations of 0.73, 0.84, 0.87, and 0.94 for the normal-hearing and SNHL groups combined. The ASSR minus behavioral difference scores were significantly larger for 500 Hz and significantly smaller for 4000 Hz compared with 1000 and 2000 Hz. Across all frequencies, the BC-ASSR correctly classified 89% of thresholds as "normal" or "elevated" (92% correct for 1000, 2000, and 4000 Hz). CONCLUSIONS: The threshold difference scores and correlations in individuals with SNHL are similar to those in normal listeners with simulated SNHL. These difference scores are also similar to those shown by previous studies for the AC-ASSR in individuals with SNHL, at least for 1000 to 4000 Hz. The BC-ASSR provides a reasonably good estimate of BC behavioral threshold in adults, especially between 1000 and 4000 Hz. Further research is required in infants with hearing loss.

Does the 40-Hz auditory steady-state response show the binaural masking level difference?

In contrast to the transient (N1-P2) and steady-state (<20 Hz) cortical responses, neither the transient (auditory brain stem response) nor the steady-state (80 Hz) brain stem responses show the binaural masking level difference (BMLD). This study determined behavioral and 40-Hz auditory steady-state response (ASSR) BMLDs for both signal and noise interaural inversions. Results showed clear behavioral BMLD but no 40-Hz ASSR BMLD. However, ASSR amplitudes were significantly smaller in dichotic compared with diotic conditions. Thus, although 40-Hz ASSR thresholds do not reflect the BMLD, the amplitude suppression under dichotic conditions may be a precursor to the subsequent <20-Hz ASSR and behavioral BMLDs.

Effect of an enlarged endolymphatic duct on bone conduction threshold.

An enlarged endolymphatic duct and sac (EDS) that makes contact with the cerebrospinal fluid­dural interface plays an important role in the pathway of bone conduction and enhances bone conduction at lower frequencies. Objectives. We investigated whether the bone conduction threshold was improved when the EDS was enlarged. Subjects and methods. Twenty-three patients (46 ears) with large vestibular aqueducts underwent standard pure tone audiometry (PTA) and magnetic resonance imaging (MRI) to investigate the relation between the diameter of the endolymphatic duct (ED) and the air or bone conduction threshold. We also investigated the relation between the volume of the EDS and the air or bone conduction threshold. Results. All ears had a mixed type hearing loss. The air­bone gaps were significantly larger at 250 and 500 Hz than at higher frequencies. The bone conduction thresholds were significantly lower at 250 Hz and 1000 Hz when the diameter of the ED was large, whereas there was no relation between the diameter of the ED and the air conduction threshold. In addition, there was no correlation between the volume of the EDS and air or bone conduction thresholds.

Otoacoustic emissions, ear fullness and tinnitus in the recovery course of sudden deafness.

OBJECTIVE: This study aimed to investigate how the symptoms of ear fullness, tinnitus and otoacoustic emissions (OAE) change in relation to the recovery course of pure tone audiometry thresholds (PTA) in sudden deafness (SD). METHODS: This study analyzed follow-up data on ear fullness, tinnitus and otoacoustic emissions of eight SD patients with good hearing improvement (Group A) and eight SD patients with poor hearing improvement (Group B) in an attempt to elucidate the behavior of these symptoms in their recovery course. This study was done until there was no change in the PTA for more than 1 week and hearing recovery was no longer expected. RESULTS: All patients from both groups had ear fullness and tinnitus in association with the onset of SD. However, these symptoms improved only in Group A. showing a significant relationship between PTA recovery and the improvement of ear fullness annoyance (P<0.05), presence of tinnitus (P<0.01), improvement in tinnitus loudness (P<0.01) and in tinnitus annoyance (P<0.01). No patients (Group A or B) had OAE responses at their first examination. In Group A, OAE responses appeared simultaneously with improvement of hearing levels in five patients (63%) and it appeared later than hearing levels improvement in the other three patients (37%) from Group A. No patient from Group B showed OAE response on follow-up. CONCLUSION: SD patients with good hearing improvement (Group A) tended to have OAE responses and the sensations of the ear fullness and tinnitus improved almost simultaneously with hearing level improvement. Their PTA improvement occurred primarily in the low to mid frequencies, with high frequencies showing less recovery. When hearing recovery was not full, OAEs did not reappear for these frequencies. Patients with poor hearing improvement tended to have absent OAEs and persistent ear fullness and tinnitus.

Cochlear modiolus and lateral semicircular canal in sudden deafness.

CONCLUSION: This study demonstrated that precise analysis shows that the inner ear shape in sudden deafness (SD) is different from that in controls in that the fluid-filled area of SD labyrinths is significantly larger than that of controls. Reduced cochlear modiolus area and inner area of the lateral semicircular canal (LSCC) may be associated with insufficient maturation of the inner ear. OBJECTIVE: The aim of this study was to quantify the morphologies of the cochlea and LSCC using magnetic resonance imaging (MRI) and to evaluate their relationships with clinical symptoms in SD. SUBJECTS AND METHODS: Twenty-six unilateral SD patients with vertigo, 26 unilateral SD patients without vertigo and a matched control group without hearing loss were studied. The areas of cochlear modioli and LSCCs were traced on the MRI console and compared between SD patients with or without vertigo and control subjects. The ratio of the LSCC fluid-filled area to the total LSCC area was used to index the degree of dysplasia. RESULTS: The cochlear modiolus area was significantly less in SD ears (4.1+/-0.2 mm2) than in controls (4.3+/-0.4 mm2). The LSCC inner area was significantly less in SD ears (6.9+/-1.7 mm2) than in controls (9.1+/-1.8 mm2). These results suggest that the fluid-filled area of SD labyrinths is significantly larger than controls. Morphology did not differ between affected and contralateral sides or between ears with or without vertigo in SD patients.

Visualization of endolymphatic hydrops in patients with Meniere's disease.

OBJECTIVE: Recently, there have been many reports of intratympanic gentamicin therapy for the treatment of intractable Meniere's disease. Intratympanic administration of steroids has also been used to treat sudden sensorineural hearing loss. We attempted to visualize how the intratympanically administered drug enters the inner ear. METHODS: Gadolinium hydrate diluted eightfold with saline was injected intratympanically through the tympanic membrane using a 23 G needle in nine patients with inner ear diseases. With a 3 Tesla magnetic resonance imaging (MRI) unit, three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging was performed. RESULTS: 3D-FLAIR MRI clearly revealed that the gadolinium entered the perilymphatic space and delineated the perilymphatic and endolymphatic spaces of the inner ear. In patients with endolymphatic hydrops, the perilymphatic space surrounding the endolymph was small or had disappeared. Gadolinium appeared first in the scala tympani of the basal turn of the cochlea and the perilymphatic space of the vestibule. One day after the intratympanic injection of gadolinium, the gadolinium was observed in almost all parts of the perilymph. Six days after the intratympanic injection, the gadolinium had almost disappeared from the inner ear. CONCLUSION: We reported the first visualization of endolymphatic hydrops in patients with Meniere's disease. The relationship between the image of the endolymphatic space and functional tests, such as electrocochleography and vestibular-evoked myogenic potential, must be examined in the near future. It is important for the development of intratympanic drug therapies for inner-ear diseases to investigate how the drugs enter and leave the inner ear.

Lateral semicircular canal and vertigo in patients with large vestibular aqueduct syndrome.

OBJECTIVE: To evaluate the hypothesis that there are differences in the morphology of the lateral semicircular canal (LSCC) between patients with large vestibular aqueduct syndrome (LVAS) and control subjects and to investigate the clinical implications of these differences. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Nine patients (two male patients and seven female patients; age range, 8-54 yr) with LVAS (one patient had unilateral LVAS, and eight patients had bilateral LVAS). Five patients had vertigo, and four patients, including the one with unilateral LVAS, did not have vertigo. MAIN OUTCOME MEASURES: The area of the LSCC was traced on the magnetic resonance imaging console and compared between LVAS patients and 12 control subjects who did not have sensorineural hearing loss. The LSCC fluid-containing area was divided by the sum of the LSCC inner area and the LSCC fluid-containing area for evaluation of the degree of the LSCC dysplasia. RESULTS: The LSCC fluid-containing ratio was significantly larger in LVAS patients than in control subjects. Moreover, the LSCC fluid-containing ratio was significantly larger in the eight ears with vertigo than in the nine ears without vertigo. There was no relationship between hearing level and the LSCC fluid-containing ratio. CONCLUSION: Patients with LVAS may have disturbed morphogenesis of both membranous and bony labyrinths. Our results reveal that the morphology of semicircular canals is clinically associated with vertigo.

Limiares auditivos para altas freqüências em adultos sem queixa auditiva / High frequency thresholds in adults without auditory complaints

Objetivo: Estudar os limiares tonais para altas freqüências em indivíduos com limiares auditivos de até 25dBNA nas oitavas de 250 a 8000 Hz, verificando a ocorrência de eventuais diferenças entre sexo e orelha testada. Método: Setenta e quatro indivíduos com dados audiológicos dentro do padräo de normalidade para a audiometria, SRT, pressäo em decapascals (daPa), pico de admitância e reflexos acústicos ipsi e contralaterais foram submetidos à audiometria de altas freqüências. Resultados: Houve diferença entre sexo masculino e feminino, com tendência a limiares em níveis de intensidade mais baixos no sexo feminino. Conclusöes: Há diferenças nos limiares de audibilidade para altas freqüências entre indivíduos do sexo feminino e masculino; ausência de diferença entre os limiares de audibilidade entre orelhas direita e esquerda; tendência à diminuiçäo do nível de intensidade dos limiares em dBNA com o aumento da freqüência.