Non-organic hearing loss: new and confirmed findings

Although non-organic hearing losses are relatively rare, it is important to identify suspicious findings early to be able to administer specific tests, such as objective measurements and specific counseling. In this retrospective study, we searched for findings that were specific ti or typical for non-organic hearing losses. Patient records from a 6year period (2003-2008) from the University ENT Department of Bern, Switzerland, were reviewed. In this period, 40 subjects were diagnosed with a non-organic hearing loss (22 children, ages 7-16, mean 10.6years; 18 adults, ages 19-57, mean 39.7years; 25 females and 15 males). Pure tone audiograms in children and adults showed predominantly sensorineural and frequency-independent hearing losses, mostly in the range of 40-60dB. In all cases, objective measurements (otoacoustic emissions and/or auditory-evoked potentials) indicated normal or substantially better hearing thresholds than those found in pure tone audiometry. In nine subjects (22.5%; 2 children, 7 adults), hearing aids had been fitted before the first presentation at our center. Six children (27%) had a history of middle ear problems with a transient hearing loss and 11 (50%) knew a person with a hearing loss. Two new and hitherto unreported findings emerged from the analysis: it was observed that a small air-bone gap of 5-20dB was typical for non-organic hearing losses and that speech audiometry might show considerably poorer results than expected from pure tone audiometr

Computer-based lung sound simulation

An algorithm for the simulation of normal and pathological lung sounds is developed. The simulation algorithm is implemented on a personal computer as well as on a digital signal processor system in real time. Normal, bronchial and tracheal breathing sounds can be generated, and continuous and discontinuous adventitious lung sounds can be added. The attributes of the individual sound components, such as loudness, frequency, duration or number of occurrences within one breathing cycle, are controlled by the user. The quality of the simulations is evaluated by sending audio tapes to 15 experienced pulmonary physicians for a formal assessment. Each tape contains five simulated lung sounds and five real lung sounds from a commercially available teaching tape, presented in random order. Simulated lung sounds are slightly better rated in terms of realism and signal quality when compared to the recordings from the teaching tape. The differences are, however, not significant. 13 out of the 15 physicians feel that computer-based lung sound simulators would be a useful and desirable teaching tool for auscultation course

Überprüfung der Bezugskurven der Schweizer Version des Freiburger Zahlen- und Einsilbertests

Zusammenfassung: Hintergrund: Die Schweizer Ausgabe des Freiburger Sprachverständlichkeitstests unterscheidet sich von der deutschen Version u.a. durch den Ersatz von 5 in der Schweiz ungebräuchlichen einsilbigen Testworten. Zudem wird keine Freifeldentzerrung benutzt und die die sich aus dem Freifeldübertragungsmaß ergebende Differenz von 6dB zwischen Lautsprecher und Kopfhörer wird bei der Kalibrierung nicht berücksichtigt. Der vor einiger Zeit eingeführte Pegelausgleich zwischen den Prüfworten und Anpassungen in der Kalibrierung veranlassten uns zur Überprüfung der Bezugskurven. Patienten/Methoden: Bei 20 normal hörenden Versuchpersonen wurde das Sprachverstehen von Zahlen und einsilbigen Wörtern mit Kopfhörern und Lautsprechern geprüft. Ergebnisse: Der Pegel für 50% Sprachverstehen lag bei Lautsprecherdarbietung im Mittel um 7,5dB niedriger ist als bei Kopfhörerdarbietung. Die mittlere Pegeldifferenz zwischen Zahlen und Einsilbern betrug 9,6dB, liegt also deutlich unter den 14dB der heute in der Schweiz empfohlenen Bezugskurven. Fazit: Die heute in der Schweiz empfohlenen Bezugskurven stimmen für Einsilber bei Kopfhörerdarbietung gut mit unseren Messungen überein, nicht aber für Zahlen und bei Lautsprecherdarbietun

Computational Simulation and 3D Virtual Reality Engineering Tools for Dynamical Modeling and Imaging of Composite Nanomaterials

An adventure at engineering design and modeling is possible with a Virtual Reality Environment (VRE) that uses multiple computer-generated media to let a user experience situations that are temporally and spatially prohibiting. In this paper, an approach to developing some advanced architecture and modeling tools is presented to allow multiple frameworks work together while being shielded from the application program. This architecture is being developed in a framework of workbench interactive tools for next generation nanoparticle-reinforced damping/dynamic systems. Through the use of system, an engineer/programmer can respectively concentrate on tailoring an engineering design concept of novel system and the application software design while using existing databases/software outputs.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

BPACE: A Bayesian, Patient-Centered Procedure for Matrix Speech Tests in Noise.

Matrix sentence tests in noise can be challenging to the listener and time-consuming. A trade-off should be found between testing time, listener's comfort and the precision of the results. Here, a novel test procedure based on an updated maximum likelihood method was developed and implemented in a German matrix sentence test. It determines the parameters of the psychometric function (threshold, slope, and lapse-rate) without constantly challenging the listener at the intelligibility threshold. A so-called "credible interval" was used as a mid-run estimate of reliability and can be used as a termination criterion for the test. The procedure was evaluated and compared to a STAIRCASE procedure in a study with 20 cochlear implant patients and 20 normal hearing participants. The proposed procedure offers comparable accuracy and reliability to the reference method, but with a lower listening effort, as rated by the listeners ( points on a 10-point scale). Test duration can be reduced by 1.3 min on average when a credible interval of 2 dB is used as the termination criterion instead of testing 30 sentences. Particularly, normal hearing listeners and well performing, cochlear implant users can benefit from shorter test duration. Although the novel procedure was developed for a German test, it can easily be applied to tests in any other language

Influence of Compression Thresholds and Maximum Power Output on Speech Understanding with Bone-Anchored Hearing Systems

Bone-anchored hearing systems (BAHS) transmit sound via osseointegrated implants behind the ear. They are used to treat patients with conductive or mixed hearing loss, but speech understanding may be limited especially in users with substantial additional cochlear hearing losses. In recent years, BAHS with higher maximum power output (MPO) and more advanced digital processing including loudness compression have become available. These features may be useful to increase speech understanding in users with mixed hearing loss. We have tested the effect of 4 combinations of two different MPO levels (highest level available and level reduced by 12 dB) and two different compression thresholds (CT) levels (50 dB and 65 dB sound pressure level) in 12 adult BAHS users on speech understanding in quiet and in noise. We have found that speech understanding in quiet was not influenced significantly by any of the changes in these two fitting parameters. In contrast, in users with average bone-conduction (BC) threshold of 25 dB or more, speech understanding in noise was improved by +0.8 dB to +1.1 dB (p 0.27). In users with better average BC thresholds than 25 dB, none of the improvement was statistically significant. Higher MPOs and possibly, to a lesser degree, lower CTs seem to be able to improve speech understanding in noise in users with higher BC thresholds, but even their combined effect seems to be limited

Potentially Inadequate Real-Life Speech Levels by Healthcare Professionals during Communication with Older Inpatients.

BACKGROUND The aim of this study was to investigate real-life speech levels of health professionals during communication with older inpatients in small group settings. METHODS This is a prospective observational study assessing group interactions between geriatric inpatients and health professionals in a geriatric rehabilitation unit of a tertiary university hospital (Bern, Switzerland). We measured speech levels of health professionals during three typical group interactions (discharge planning meeting (n = 21), chair exercise group (n = 5), and memory training group (n = 5)) with older inpatients. Speech levels were measured using the CESVA LF010 (CESVA instruments s.l.u., Barcelona, Spain). A threshold of <60 dBA was defined as a potentially inadequate speech level. RESULTS Overall, mean talk time of recorded sessions was 23.2 (standard deviation 8.3) minutes. The mean proportion of talk time with potentially inadequate speech levels was 61.6% (sd 32.0%). The mean proportion of talk time with potentially inadequate speech levels was significantly higher in chair exercise groups (95.1% (sd 4.6%)) compared to discharge planning meetings (54.8% (sd 32.5%), p = 0.01) and memory training groups (56.3% (sd 25.4%), p = 0.01). CONCLUSIONS Our data show that real-life speech level differs between various types of group settings and suggest potentially inadequate speech levels by healthcare professionals requiring further study

A two-microphone noise reduction system for cochlear implant users with nearby microphones. Part II: Performance Evaluation

Users of cochlear implants (auditory aids, which stimulate the auditory nerve electrically at the inner ear) often suffer from poor speech understanding in noise. We evaluate a small (intermicrophone distance 7 mm) and computationally inexpensive adaptive noise reduction system suitable for behind-the-ear cochlear implant speech processors. The system is evaluated in simulated and real, anechoic and reverberant environments. Results from simulations show improvements of 3.4 to 9.3 dB in signal to noise ratio for rooms with realistic reverberation and more than 18 dB under anechoic conditions. Speech understanding in noise is measured in 6 adult cochlear implant users in a reverberant room, showing average improvements of 7.9–9.6 dB, when compared to a single omnidirectional microphone or 1.3–5.6 dB, when compared to a simple directional two-microphone device. Subjective evaluation in a cafeteria at lunchtime shows a preference of the cochlear implant users for the evaluated device in terms of speech understanding and sound quality

Effects of temporal fine structure preservation on spatial hearing in bilateral cochlear implant users

Typically, the coding strategies of cochlear implant audio processors discard acoustic temporal fine structure information (TFS), which may be related to the poor perception of interaural time differences (ITDs) and the resulting reduced spatial hearing capabilities compared to normal-hearing individuals. This study aimed to investigate to what extent bilateral cochlear implant (BiCI) recipients can exploit ITD cues provided by a TFS preserving coding strategy (FS4) in a series of sound field spatial hearing tests. As a baseline, we assessed the sensitivity to ITDs and binaural beats of 12 BiCI subjects with a coding strategy disregarding fine structure (HDCIS) and the FS4 strategy. For 250 Hz pure-tone stimuli but not for broadband noise, the BiCI users had significantly improved ITD discrimination using the FS4 strategy. In the binaural beat detection task and the broadband sound localization, spatial discrimination, and tracking tasks, no significant differences between the two tested coding strategies were observed. These results suggest that ITD sensitivity did not generalize to broadband stimuli or sound field spatial hearing tests, suggesting that it would not be useful for real-world listening