Low-Frequency Hearing Preservation With Long Electrode Arrays: Inclusion of Unaided Hearing Threshold Assessment in the Postoperative Test Battery.

Purpose The goal of this work was to evaluate the low-frequency hearing preservation of long electrode array cochlear implant (CI) recipients. Method Twenty-five participants presented with an unaided hearing threshold of ≤ 80 dB HL at 125 Hz pre-operatively in the ear to be implanted. Participants were implanted with a long (31.5-mm) electrode array. The unaided hearing threshold at 125 Hz was compared between the preoperative and postoperative intervals (i.e., initial CI activation, and 1, 3, 6, 9, and 12 months after activation). Results Eight participants maintained an unaided hearing threshold of ≤ 80 dB HL at 125 Hz postoperatively. The majority (n = 5) demonstrated aidable low-frequency hearing at initial activation, whereas 3 other participants experienced an improvement in unaided low-frequency hearing thresholds at subsequent intervals. Conclusions CI recipients can retain residual hearing sensitivity with fully inserted long electrode arrays, and low-frequency hearing thresholds may improve during the postoperative period. Therefore, unaided hearing thresholds obtained within the initial weeks after surgery may not reflect later hearing sensitivity. Routine measurement of postoperative unaided hearing thresholds-even for patients who did not demonstrate aidable hearing thresholds initially after cochlear implantation-will identify CI recipients who may benefit from electric-acoustic stimulation. Supplemental Material https://doi.org/10.23641/asha.11356637.

[Medical and social rehabilitation of hearing impairment from occupational noise]. / Meditsinskaia i sotsial'naia reabilitatsiia lits s narusheniiami slukha ot proizvodstvennogo shuma.

The article presents the main provisions of medical and social rehabilitation of various hearing disorders caused by industrial noise. Two forms of hearing organ pathology in accordance with ICD-10 are distinguished: 'Adverse effects of industrial noise' - Z57.0 and 'hearing Loss caused by noise' - H83.3. The main methods of drug and non-drug rehabilitation of patients with signs of adverse effects of noise on the hearing organ and medical and social bases of rehabilitation of patients with severe clinical forms of hearing loss from noise are revealed. The basic principles of medical and social expertise in professional hearing loss: determination of the date of establishment and degree of loss of professional capacity for work, the need of the victim in medical, social and professional rehabilitation, recognition of the victim as a disabled person due to occupational disease, the development of the rehabilitation program of the victim in the workplace. References to the main Federal and industry documents of the Ministry of labor and the Ministry of health regulating medical and social rehabilitation are given.

Safety limit warning levels for the avoidance of excessive sound amplification to protect against further hearing loss.

OBJECTIVE: To determine safe output sound pressure levels (SPL) for sound amplification devices to preserve hearing sensitivity after usage. DESIGN: A mathematical model consisting of the Modified Power Law (MPL) (Humes & Jesteadt, 1991 ) combined with equations for predicting temporary threshold shift (TTS) and subsequent permanent threshold shift (PTS) (Macrae, 1994b ) was used to determine safe output SPL. STUDY SAMPLE: The study involves no new human subject measurements of loudness tolerance or threshold shifts. PTS was determined by the MPL model for 234 audiograms and the SPL output recommended by four different validated prescription recommendations for hearing aids. RESULTS: PTS can, on rare occasion, occur as a result of SPL delivered by hearing aids at modern day prescription recommendations. The trading relationship of safe output SPL, decibel hearing level (dB HL) threshold, and PTS was captured with algebraic expressions. Better hearing thresholds lowered the safe output SPL and higher thresholds raised the safe output SPL. CONCLUSION: Safe output SPL can consider the magnitude of unaided hearing loss. For devices not set to prescriptive levels, limiting the output SPL below the safe levels identified should protect against threshold worsening as a result of long-term usage.

Crossmodal plasticity in auditory, visual and multisensory cortical areas following noise-induced hearing loss in adulthood.

Complete or partial hearing loss results in an increased responsiveness of neurons in the core auditory cortex of numerous species to visual and/or tactile stimuli (i.e., crossmodal plasticity). At present, however, it remains uncertain how adult-onset partial hearing loss affects higher-order cortical areas that normally integrate audiovisual information. To that end, extracellular electrophysiological recordings were performed under anesthesia in noise-exposed rats two weeks post-exposure (0.8-20 kHz at 120 dB SPL for 2 h) and age-matched controls to characterize the nature and extent of crossmodal plasticity in the dorsal auditory cortex (AuD), an area outside of the auditory core, as well as in the neighboring lateral extrastriate visual cortex (V2L), an area known to contribute to audiovisual processing. Computer-generated auditory (noise burst), visual (light flash) and combined audiovisual stimuli were delivered, and the associated spiking activity was used to determine the response profile of each neuron sampled (i.e., unisensory, subthreshold multisensory or bimodal). In both the AuD cortex and the multisensory zone of the V2L cortex, the maximum firing rates were unchanged following noise exposure, and there was a relative increase in the proportion of neurons responsive to visual stimuli, with a concomitant decrease in the number of neurons that were solely responsive to auditory stimuli despite adjusting the sound intensity to account for each rat's hearing threshold. These neighboring cortical areas differed, however, in how noise-induced hearing loss affected audiovisual processing; the total proportion of multisensory neurons significantly decreased in the V2L cortex (control 38.8 ± 3.3% vs. noise-exposed 27.1 ± 3.4%), and dramatically increased in the AuD cortex (control 23.9 ± 3.3% vs. noise-exposed 49.8 ± 6.1%). Thus, following noise exposure, the cortical area showing the greatest relative degree of multisensory convergence transitioned ventrally, away from the audiovisual area, V2L, toward the predominantly auditory area, AuD. Overall, the collective findings of the present study support the suggestion that crossmodal plasticity induced by adult-onset hearing impairment manifests in higher-order cortical areas as a transition in the functional border of the audiovisual cortex.

[The Königsteiner Empfehlung of 2012 - essential alterations and modifications]. / Die Königsteiner Empfehlung von 2012 - Wesentliche Neuerungen und Änderungen.

BACKGROUND: Since 1974, the recommendation for assessment of hearing impairment caused by noise - formerly known as "Königsteiner Merkblatt" (now: "Königsteiner Empfehlung") - has been representing the state of the art for the assessment of the occupational disease BK-No. 2301. It was updated several times, the last time in 2012. It provides a summary of the current medical knowledge. A new measurement for the entire working life - the Effective Noise Dose by Liedtke - was introduced. Otoacoustic emissions (OAE) are now the crucial tests in order to detect a hair cell dysfunction. As from now the tinnitus has to be put under a more comprehensive examination. On the strength of post experience the previous speech audiometry (Freiburger Test) is reliable, it was retrained. In future the indication for hearing aids will be oriented towards the aid guidelines of the legal health insurance. The questionnaire for the expert opinion was revised and the fee was adapted.

The use of Nucleus CI422 in a ski-slope high-frequency hearing loss and chronic external ear pathology: a case study.

OBJECTIVE AND IMPORTANCE: This case report illustrates the ongoing extending criteria for cochlear implantation (CI). It reinforces the statement that patients who do not fulfill the standard criteria for CI should be carefully considered on an individual basis. CLINICAL PRESENTATION: The patient on this report presented with a ski-slope high-frequency hearing loss and chronic external ear canal infections. The latter precluded the consistent use of hearing aids with moulds. His speech discrimination in quiet and in noise was poor and his hearing loss was interfering with his ability to work. INTERVENTION: After years of frustration, this patient decided to risk losing his low-frequency residual hearing and was implanted with the new Nucleus CI422 (Cochlear Ltd). CONCLUSION: Hearing preservation was achieved and he gained a remarkable improvement in his hearing performance. It is thought that his outcomes are the result of the combination of hearing presentation surgery, electrode design, and intensive auditory training.

Increased inner ear susceptibility to noise injury in mice with streptozotocin-induced diabetes.

We aimed to investigate the pathophysiology of diabetes-associated hearing impairment in type 1 diabetes using mice with streptozotocin-induced diabetes (C57BL/6J; male). Hearing function was evaluated 1, 3, and 5 months after induction of diabetes (five diabetic and five control animals per time point) using auditory-evoked brain stem responses (ABRs). Mice (four diabetic and four control) were exposed to loud noise (105 dB) 5 months after induction of diabetes. ABRs were measured before and after noise exposure. Cochlear blood flows were measured by laser-Doppler flowmeter. Spiral ganglion cells (SGCs) were counted. Vessel endothelial cells were observed by CD31 immunostaining. Chronologic changes in the ABR threshold shift were not significantly different between the diabetic and control groups. However, vessel walls in the modiolus of the cochleae were significantly thicker in the diabetic group than the control group. Additionally, recovery from noise-induced injury was significantly impaired in diabetic mice. Reduced cochlea blood flows and SGC loss were observed in diabetic mice cochleae after noise exposure. Our data suggest that diabetic cochleae are more susceptible than controls to loud noise exposure, and decreased cochlear blood flow due to sclerosis of the vessels and consequent loss of SGCs are possible mechanisms of hearing impairment in diabetic patients.

Impact of hearing loss in the workplace: raising questions about partnerships with professionals.

The number of adults with hearing loss who continue to work later in life is growing. Persons with hearing loss are generally unaware of the role that audiologists, occupational therapists, and vocational rehabilitation counsellors might play in the assessment of the workplace environment and appropriate accommodations. Three narratives of adults with hearing loss are used to demonstrate the gaps in accessing information, technology and services needed to maintain optimal work performance and productivity. The lack of recognition of the multidimensional needs of older workers with hearing loss and the lack of timely coordination of services led to all three persons acting alone in trying to access services and supports. In two of the three cases the impact of the hearing loss resulted in further unexpected losses such as the loss of employment and the loss of a worker-identity. There is an urgent need for partnering with persons who are hard of hearing to develop new strategies for knowledge exchange, more thorough assessment of hearing demands and modifications in the workplace, and interdisciplinary approaches to service specific to the needs of hard of hearing persons.

[New aspects of hearing aid fitting in noise-induced hearing loss]. / Neue Aspekte zur Hörgeräteversorgung bei Lärmschwerhörigkeit.

In the past hearing aid fitting frequently turned out to be a problem in patients with noise-induced hearing loss. Selective amplification in the high frequency range and at the same time natural sound and appropriate wearing comfort (open fitting) could not be achieved in numerous cases. Today these problems can be tackled by modern hearing aid technology providing us with efficient feedback suppression algorithms making open fittings possible for many more patients. This development is particularly beneficial for patients with noise-induced hearing loss. Unfortunately, open fitting is in opposition to wearing hearing aids at noisy workplaces. Tight fittings, however, can be used at work if a special listening program for noisy conditions is available. This dilemma is discussed and possible solutions are pointed out.

Selected complex auditory disorders.

This article provides an overview of four auditory disorders relevant generally to adults and especially to veterans. The disorders are noise-induced hearing loss, idiopathic sudden sensorineural hearing loss, otosclerosis, and Méniàre's disease. Sensorineural hearing loss characterizes each, but additional aspects vary with each of the four conditions. This article describes the conditions, discusses their diagnoses and treatments, and outlines current and suggested rehabilitation. The emphasis is on recent advances, some of which await confirmation prior to possible acceptance as standard practice.

[Inner ear damage due to leisure and broadband noise. An experimental study on initial and permanent functional and morphological damage]. / Innenohrschäden durch Freizeitlärm und Breitbandrauschen. Eine experimentelle Studie zu initialen und permanenten funktionellen und morphologischen Schäden.

The initial and permanent effects of leisure noise (toy pistols, rock music) compared to broadband noise were examined in 68 guinea pigs. Auditory threshold shifts at 1.5, 2, 3, 4, 6, 8, 12 und 16 kHz were registered before and immediately after exposure as well as on days 1, 2, 3, 5,7 and 21 post-exposure using the auditory brain stem response (ABR) technique. In order to examine cilia and hair cell damage in eight cochlear frequency regions (<0,4 kHz, 0,4-0,8 kHz, 0,8-1.5 kHz, 1.5-3 kHz, 3-5 kHz, 5-11.5 kHz, 11.5-26 kHz und >26 kHz), cytocochleograms were performed immediately after exposure and on days 1, 7 and 21.Frequency dependent functional or morphological damage was found which depended on the type of trauma tested. All results were highly significant ( P<0.001). The results show that partial recovery of hearing occurred within 3 days of acute acoustic trauma induced by toy pistols and within 1 day after exposure to rock music or broadband noise. There was no further recovery of hearing within the following 18 and 20 days, respectively. Furthermore, permanent threshold shifts after exposure to rock music or broadband noise were not associated with cilia and/or hair cell damage.

Effects of high-frequency emphasis and compression time constants on speech intelligibility in noise.

The objectives of the study were to evaluate the effect of different settings with regard to speech intelligibility in noise both objectively and subjectively and thus determine a favoured setting of compression time parameters, pre-set program (high-frequency emphasis) or combination for each individual user in a prospective study. Another objective was to evaluate the relationship between patient characteristics (e.g. slope of hearing loss) and favoured settings. In total, 38 subjects divided over five audiological centres were fitted with the Philips Spaceline D71-40 BTE digital hearing aid. Subjects were asked to compare three predefined compression algorithms with different time constants, slow (indicated by the manufacturer as AVC), intermediate (NORMAL) and fast (SYLLABIC) over two 4-week periods using the intermediate setting in both comparisons and randomizing over the fast and slow conditions. A randomization determined whether a subject started with the comfort-oriented pre-set program (AUTO) or the speech intelligibility-oriented setting with high-frequency emphasis (SPIN). In a third 4-week period, the pre-sets AUTO and SPIN were compared using the setting of the compression time constants that gave the best results during the first two periods. Comparisons were made using a standard speech-in-noise test with three types of noise: continuous speaker noise, modulated ICRA-4 noise, and car noise. The patients were also asked to fill in a Dutch translation and adaptation of the APHAB questionnaire to indicate their impression of performance. The results indicate that no compression algorithm, pre-set or combination is favoured overall. The largest improvement in speech-in-noise scores was found with syllabic compression. The advantageous effect of high-frequency emphasis after optimization of compression timing is small. The APHAB showed that users tend to prefer the SPIN setting. We found no relationship between favoured compression or pre-set and the degree or steepness of the hearing loss User preference and best performance in noise do not always coincide. Acclimatization may play a role. It could be advisable to let a user listen to a subjectively less favoured condition for at least some time if an optimal setting for speech intelligibility in noise is preferred over comfort.

Behavioural awareness, interaction and counselling education in audiological rehabilitation: development of methods and application in a pilot study.

In conventional audiological rehabilitation, the hearing therapist interacts with the hearing-impaired person and with significant others. In order to strengthen the personality and self-confidence of the hearing-impaired individual, a different strategy was designed and implemented whereby the pedagogic interaction was directed only towards the hearing-impaired individual, who in turn worked as a tutor/aid/counsellor to the communication partner. On the basis of an interactive communication model, new methods for rehabilitation of subjects with moderate hearing impairment were developed and evaluated in a pilot study on 13 men with noise-induced hearing loss. A course programme was developed with three main active components: (1) increased insight and knowledge; (2) education as counsellors with the ability to focus on the problems of the communication partner; and (3) motivation to change through group discussion and reflexive conversation. Increased insight and knowledge were obtained through test and training experiences in a sound environmental chamber, tutorials and discussions. The pedagogic training focused on helping the hearing-impaired subjects to become able communication counsellors in relation to their interlocutors. An act-react, offensive-defensive paradigm was used in conjunction with transactional analysis. Results of the pilot study were evaluated using questionnaires, interviews and a method of dialogue analysis. The results were evaluated for the hearing-impaired and the partner and in recordings of conversations in the home environment. There were clearly positive cognitive and emotional effects seen in the inquiries and interviews. The observations from the dialogue analysis indicated only small effects, with the exception of the two individuals with the most pronounced functional impairment, for whom dialogue was improved after the course. It was concluded that these new methods could contribute new possibilities in rehabilitation programmes, emphasizing the shared responsibility for communication and the unique competence and abilities of the hearing-impaired person.