Hearing Impression Research Articles

Auralization and Visualization for Infrastructure Planning in the Joint Project "EAV-Infra"

Within the joint research project "Real-time Calculation, Auralization and Visualization of Sound Propagation and Noise Protection Measures for Infrastructure Projects" (EAV-Infra), funded by the Federal Ministry for Economic Affairs, the potentials of digital infrastructure planning based on Building Information Modeling (BIM) and the auralization of different states of planning will be combined. In this contribution, the objectives of the project will be presented with particular focus on the auralization. Currently, the effectiveness of noise mitigation measures like acoustic barriers or rail dampers is evaluated and communicated mostly by means of SPL values. Through auralization, a more vivid impression of different states of planning can be given during the whole planning process. In EAV-Infra, the auralization will be based on audio data of partial sound sources taken from real train passings. The data will be collected at various sites using a newly developed MEMS microphone array. To achieve a realistic hearing impression at the receiver position, a suitable model of the sound propagation will be implemented, which allows for a simulation in real time. In a last step, the partial sound source's signals will be convolved with the calculated sound propagation to synthesize the signal at the receiver position.

Research on auditory signal characteristics that support the safety and security of daily life―From an age-related hearing change and impression evaluation experiment in healthy adult subjects―

Research on auditory signal characteristics that support the safety and security of daily life―From an age-related hearing change and impression evaluation experiment in healthy adult subjects―

Is the cochlear implant a successful long-term solution for single-sided deaf and asymmetric hearing-impaired patients?

PurposeWe investigated the long-term results of cochlear implant (CI) recipients with asymmetric hearing loss (AHL) or single-sided deafness (SSD). We focused on wearing behavior, audiometric hearing rehabilitation, and subjective benefits of the CI. CI is expected to improve audiological results, subjective hearing perception, and tinnitus burden.MethodsSpeech recognition in background noise and sound localization were assessed preoperatively and after at least six years of CI experience. Validated questionnaires determined the subjective benefit of CI use and the subjective evaluation of tinnitus.ResultsOver 80% of the included AHL and SSD CI recipients used their CI between 6 and 10 h daily; four subjects with SSD were non-users. Speech recognition in background noise and sound localization improved significantly compared with the unaided preoperative situation. Additionally, CI improved subjective speech intelligibility and spatial hearing impression while reducing tinnitus burden.ConclusionSubjects with AHL and SSD benefit from CI, subjectively and audiologically. Cochlear implant is a successful long-term treatment for AHL and SSD.

Subjective Hearing Impression and Quality of Life in Patients With Bilateral Active Middle Ear Implants.

This study compared the quality of life in patients with bilateral active middle ear implants to their quality of life when they were unilaterally implanted. Twenty-one patients implanted sequentially with the Vibrant Soundbridge (VSB) active middle ear implant completed quality-of-life surveys. The patients were asked to rate whether and to what extent their quality of life has changed upon receiving a second VSB. Hearing-specific quality of life was assessed with the Speech, Spatial, and Qualities of Hearing Scale (SSQ12-B), and general quality of life was with the Glasgow Benefit Inventory (GBI). In addition, the patients completed a health-related quality-of-life questionnaire (AQoL-8D). Finally, the changes in hearing-related and general quality of life were correlated to the change in word recognition ability after implantation of the second VSB (Freiburg monosyllabic word test; unilateral VSB versus bilateral VSB at 65 dB SPL). On the SSQ12, subjects scored a median of + 2.73 (p < 0.001; significantly different from zero) on a scale of -5 to + 5 where 0 indicates no change. All three subscores showed significant improvement. On the GBI, patients reached a median overall score of + 23.6 (p < 0.001; significantly different from zero) on a scale of -100 to + 100 where 0 indicates no change. Here, the improvement was mainly visible in the general subscore, whereas the social support and physical health subscores did not change due to the intervention. Both subjective benefit rating scores strongly correlated with the change in word recognition scores, suggesting that both hearing and general quality of life improved with increased word recognition due to bilateral VSB use. No significant correlation was found between the subjects' general health (as measured by AQoL-8D utility scores) and SSQ12-B or GBI overall scores. Usage of a second active middle ear implant substantially improved our patients' subjective hearing and general quality of life compared with unilateral use. The increase in quality of life may be linked to improved speech understanding due to bilateral use of a middle ear implant. Furthermore, these outcomes were not influenced by our patients' general health state at the time of survey.

Decellularized equine carotid artery layers as matrix for regenerated neurites of spiral ganglion neurons.

Today’s best solution in compensating for sensorineural hearing loss is the cochlear implant, which electrically stimulates the spiral ganglion neurons in the inner ear. An optimum hearing impression is not ensured due to, among other reasons, a remaining anatomical gap between the spiral ganglion neurons and the implant electrodes. The gap could be bridged via pharmacologically triggered neurite growth toward the electrodes if biomaterials for neurite guidance could be provided. For this, we investigated the suitability of decellularized tissue. We compared three different layers (tunica adventitia, tunica media, and tunica intima) of decellularized equine carotid arteries in a preliminary approach. Rat spiral ganglia explants were cultured on decellularized equine carotid artery layers and neurite sprouting was assessed quantitatively. Generally, neurite outgrowth was possible and it was most prominent on the intima (in average 83 neurites per spiral ganglia explants, followed by the adventitia (62 neurites) and the lowest growth on the media (20 neurites). Thus, decellularized equine carotid arteries showed promising effects on neurite regeneration and can be developed further as efficient biomaterials for neural implants in hearing research.

Vibration of the Basilar Membrane and Fluid Pressure Distribution in the Human Cochlea

AbstractThe human inner ear or cochlea is a bone structure of spiral shape and is composed of mainly two conical chambers which are filled with fluid and separated by a soft membrane, referred to as the basilar membrane. At the apical end, both chambers are connected through a small opening, the helicotrema. At the base, the chambers are closed by the stapes footplate and the round window membrane. In case of a normal ear, sound is received by the eardrum, transmitted through the middle ear ossicles and finally excites the inner ear fluid through the vibration of the stapes footplate. According to present hearing theory, this leads to pressure waves in the cochlear fluid which in turn results in characteristic vibration behavior of the basilar membrane. Related to the sound frequency, hair cells in certain areas of the basilar membrane are stimulated and cause hearing nerve stimulation. In order to predict the effect of inner ear diseases on hearing impression as well as to develop new hearing implants, a deeper understanding of the cochlear dynamics is needed. However, since the cochlea represents a closed hydraulic system with a complex geometry, the motion of the basilar membrane as well as the fluid pressure can hardly be measured. Therefore, a numerical model of the uncoiled cochlea is developed representing the fundamental physical effects occurring in the cochlea. Taking the fluid‐structure interactions into account, the transfer behavior of the cochlear system is investigated for different excitation frequencies within the auditory frequency range of humans. The simulations show the passive vibration of the basilar membrane resulting in the characteristic traveling wave. These results allow to study the mapping of the excitation frequency to its characteristic pattern along the basilar membrane, called tonotopy. Further, the spatial fluid pressure distribution along the cochlear chambers is evaluated and allows new insights into the cochlear physics. (© 2017 Wiley‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Subjective Comparison Experiments of DMS and Conventional Stereo

Multi-channel dynamic matrix sound system (DMS) is a multi-channel input and output sound system which is based on source synthesis and Huygens' principle. The sound sources are recorded by microphone array and multi-channel independent recording, instead of the field. This paper describes the results of the subjective evaluation experiments between DMS and conventional stereo system by the semantic differential (SD) method. Five parts of the audio materials and a training material, including the human voice, music, sound effects, were used as the stimuli. All of the stimuli were recorded by the DMS and conventional stereo system respectively. The results proof that the effectiveness of DMS, which has a higher level of sound quality and can give the audience the experience of dynamic subjective feelings compared with conventional stereo system. Furthermore, sound designers must carefully consider the influence of gender, age, preferences on the hearing impression.

The effects of intelligibility and variability on cognitive performance and acoustic comfort

Open-plan offices are very popular due to some assumed economic and organizational advantages. These benefits are confronted with typical drawbacks, i.e. office noise and lack of speech privacy. Ambient speech caused by conversations of colleagues is assumed to impair office workers' individual task performance at silent, concentrated work. The Speech Transmission Index (STI) is proposed to be a predictor of how much performance is reduced due to ambient speech in dependency of its intelligibility (Hongisto, 2005). Target values for the acoustic quality of open-plan offices were defined which account for the special importance of speech intelligibility (e.g. Virjonen et al., 2009). Fluctuation strength, a hearing impression due to slow modulations of amplitude or frequency, has also been shown to predict the loss of individual task performance (Schlittmeier et al. 2011). The relevance of both variables is systematically explored with regard to cognitive performance and acoustic comfort. Based on these results target values are discussed.

Ergebnisse otochirurgisch operierter Patienten mit Akustikusneurinom

The surgical therapy of acoustic neuromas has been seen critically lately. Alternative methods like the gamma-knife treatment open a wide field of discussion. The results of 392 patients are presented operated on via a middle fossa approach between 1989 and 2004. Hearing preservation according to the 50:50 rule (hearing loss less than 50 dB in pure tone audiogram 500-1000-2000 Hz, speech discrimination>50%) was possible in 59.7% of patients. A hearing impression up to 90 dB was recognized in 83.1%, 16.9% of cases were deaf. There was no difference between tumors confined to the inner ear canal and tumors extending into the cerebello pontine angle. There was also no difference between tumors up to a volume of 100 mm3 and tumors between 100 mm3 and 500 mm3. Acoustic neuroma confined to the internal meatus or with little extend into the cerebello pontine angle (i. e. no contact to structures of the brain stem or vessels of the posterior fossa) are feasible for resection via the middle fossa approach. The possibility of hearing preservation and low morbidity makes it the treatment of choice for this group of tumors.

Acetylcholine injection into the amygdala elicits vocalization in domestic pigs ( Sus scrofa)

In a pilot study we have injected the amygdala of five female pigs (age 8 weeks) with acetylcholine (ACh, 5.5 μM/20 μl) and recorded short latency utterances. The evoked vocalizations displayed the characteristics of natural screams in sonagram appearance and hearing impression. Quantitative analyses, too, revealed the similarity of the ACh-evoked vocalizations with natural screaming. The results demonstrate for the first time that aversive vocalizations can be triggered by cholinergic amygdala stimulation.

Integrierte Tinnitusintensivbehandlung: Konzept und erste praktische Erfahrungen

In recent years, no major advances have been made in understanding the mechanisms underlying the development of tinnitus. Hence, the present therapeutic strategies aim at decoupling the subconscious from the perception of tinnitus. Mindful of the lessons drawn from existing tinnitus retraining and desensitisation therapies, a new integrated day hospital strategy of treatment lasting 7-14 days has been developed at the Charité Hospital and is presented in the present paper. The strategy for treating tinnitus in the proximity of patient domicile is designed for patients who feel disturbed in their world of perception and their efficiency due to tinnitus and give evidence of mental and physical strain. In view of the etiologically non-uniform and multiple events connected with tinnitus, consideration was also given to the fact that somatic and psychosocial factors are equally involved. Therefore, therapy should aim at diagnosing and therapeutically influencing those psychosocial factors that reduce the hearing impression to such an extent that the affected persons suffer from strain. The first results of therapy-dependent changes of 46 patients suffering from chronic tinnitus are presented. The data were evaluated before and after 7 days of treatment and 6 months after the end of treatment. Immediately after the treatment, the scores of both the tinnitus questionnaire (Goebel and Hiller) and the subscales improved significantly. These results were maintained during the 6-month post-treatment period and even improved.

床衝撃音レベルの評価指標及び主観評価との対応に関する研究

We experimented rating of impact sound pressure level by hearing impression with floor impact sound including life sound. And we select the best evaluation index that has a high correlation in hearing impression. As the result, it is shown that maximum A-weighted impact sound pressure level LA,Fmax is better for heavy impact source than L-Number, and arithmetic average of sound pressure levels in octave bands L (63-4k) is better for light impact source than L-Number. Next, we examined the correspondence of LA, Fmax, L (63-4k) and hearing impression.

Factors influencing the subjective rating of tonal components in noise

If environmental or artificial noises contain tonal components, they are more annoying than noises without tonal components. Therefore the German norm, DIN 45681 (draft): ‘‘Detection of tonal components of noise and determination of a tone adjustment for the assessment of noise immisions’’ was proposed to quantify this increased annoyance. Within this definition the effects of the tonal components are reduced to the increasing annoyance of the signals. In the literature no satisfying data exists about the subjective ratings of tonal components in noises (in German called ‘‘Tonhaltigkeit’’). For this reason the present study investigates the influence of selected physical parameters on subjective ratings of the ‘‘Tonhaltigkeit.’’ An adaptive procedure is used to adjust the hearing impression ‘‘Tonhaltigkeit’’ of different noises to a reference signal consisting of a single sinusoidal.

A system for natural reproduction of sound and vibration

For the psychoacoustical evaluation of sound, usually artificial head recordings are reproduced with headphones or loudspeakers. Interior aircraft or car noise, however, contains high sound and vibration energy components below 20 Hz. If these spectral components are not reproduced, subjects often complain about an unnatural hearing impression. In this paper, a reproduction system is presented that extends the audio bandwidth down to 2 Hz. For presenting vibration signals, the subject’s chair (e.g., aircraft or car seat) is mounted on an exciter system. The three-dimensional vibration signal spans the frequency range from 6 to 80 Hz. A report is given on psychoacoustic experiments and results with this sound and vibration reproduction system.

In vivo studies of a piezoelectric implantable hearing aid transducer in the cat

Recently, we presented an implantable piezoelectrical hearing aid transducer. Its characteristics make it suitable for implantation in patients with sensorineural hearing loss. The transducer transmits micromechanical vibrations instead of sound into the hearing organ. Efficiency of the transducer implant was investigated in ten cat ears. After determining preoperative (acoustical) BERA threshold, the middle ear was opened and the piezoelectrical transducer coupled to various ossicles or the perilymph. BERA responses were recorded following stimulation of umbo, long incus process, stapes head, stapes foot plate, and vestibulum. By comparing the acoustical and mechanical threshold, a correlation was found between the stimulus level of acoustical and mechanical stimulation. An electrical transducer voltage of 1 Vrms was equivalent to sound-pressure levels between 100 and 128 dB SPL at the tympanic membrane. To judge hearing impression, stimulus-dependent latencies of the early acoustically and mechanically evoked potentials (waves P1 to P5) and their thresholds were analyzed. After coupling the piezoelectrical transducer to the long incus process, latencies corresponded well to stimulation. They were almost completely similar when the equivalent sound-pressure level of 100 dB SPL was achieved by the transducer voltage level.

骨格性反対こう合者における無声摩擦音／∫／の音響的特徴と聴覚印象

Speech disorders in patients with severe skeletal class III malocclusion are predominantly distortion, and distortion on the fricatives occurs most frequently. However, the acoustic characteristics of these distorted fricatives and the mechanisms of speech production have not been clarified.The fricative /s/ pronounced by the skeletal class ET patients before and after orthognathic surgery were acoustically analyzed, and the acoustic characteristics of the distorted fricative /s/ and the cause of distortion were reported.In this article, the fricative /∫/, which was pronounced by the orthognathic surgical patients, was acoustically analyzed to investigate the acoustic characteristics of the distorted /∫/ and the cause of distortion, and the relationship between the acoustic characteristics and the hearing impression was determined. The fricative /∫/ is the same as fricative /s/ in the manner of articulation but differs in the place of articulation.The results of this study were as follows:1) The sound pressure level of the middle frequency range, which was around 5kHz on the presurgical spectrum of the patients, was found to be lower than that of normal subjects, but the level of this range on the postsurgical spectrum rose. 2) The pressure level of the middle frequency range of the fricative /∫/ was influenced by the resonance of the vocal tract. 3) The naturality of the fricative /∫/ also improved after surgery in the results of the hearing test. Therefore, the distortion of /∫/ was caused by the deformity of the vocal tract of severe skeletal class III malocclusion.

New Methods in Architectural Acoustic Investigations for Evaluating the Acoustic Qualities of Concert Halls

In recent years efforts in architectural acoustics investigations have concentrated upon correlation between the physical data of a concert hall, on the one hand, and hearing events and judgments in the hall on the other hand. Contrary to earlier investigations in this field, these efforts do not concentrate upon finding the subjective correlate to an individual physical characteristic, e.g., reverberation time versus frequency, early decay time, “Deutlichkeit,” and so on; nowadays, instead, the total hearing impression of an observer in a concert hall—the “Hörsamkeit”—is correlated with the total set of physical data measured in this room. L. Beranek, who started his work in architectural acoustics with exact calculations and measurements of rectangular rooms at the laboratory of F. V. Hunt, Harvard University, described the first important effort in this direction about 10 years ago. A deficiency of this and similar trials is the uncertainty of the subjective observations and judgments. In this respect in recent years, a great improvement has been attained by refining the collection of subjective judgments and by the aid of improved electro-acoustic transmission systems. A survey of these systems—especially head-related stereophonic systems—will be given and preliminary results will be reported.

New Methods in Architectural Acoustic Investigations to Evaluate the Acoustic Qualities of Concert Halls

In recent years, efforts in architectural acoustics investigations have concentrated upon correlation between the physical data of a concert hall, on the one hand, and hearing events and judgments in the hall on the other hand. Contrary to earlier investigations in this field, these efforts do not concentrate upon finding the subjective correlate to an individual physical characteristic, e.g., reverberation time versus frequency early decay time, “Deutlichkeit,” and so on; nowadays, instead, the total hearing impression of an observer in a concert hail—the “Hörsamkeit”—s correlated with the total set of physical data measured in this room. L. Beranek, who started his work in architectural acoustics with exact calculations and measurements of rectangular rooms at the laboratory of F. V. Hunt, Harvard University, described the first important effort in this direction about 10 years ago. A deficiency of this and similar trials is the uncertainty of the subjective observations and judgments. In this respect in recent years, a great improvement has been attained by refining the collection of subjective judgments and by the aid of improved electro-acoustic transmission systems. A survey of these systems—especially head-related stereophonic systems—will be given and preliminary results will be reported. [The material in this paper is shared with this session and the F. V. Hunt Memorial Session I.]