Monaural Research Articles

Deep Neural Network Based Monaural Speech Enhancement with Sparse Non-Negative Matrix Factorization

Deep Neural Network Based Monaural Speech Enhancement with Sparse Non-Negative Matrix Factorization

Sighted humans show enhanced sensitivity for horizontal but not vertical audio localization

Introduction Experiments on humans and animals indicate that auditory localization develops through the association of sets of monaural and binaural cues and locations in space: this calibration process in guided by vision (Knudsen, 1989).The auditory system lacks a straightforward correspondence between external spatial locations and sensory receptive fields (Ahveninen et al ., 2014), so the development of auditory localization is more complex than visual localization. Aim The main aim is to assess if the development of audio spatial localization in sighted humans:Differs for horizontal and vertical dimensionsDepends on: a)Type of sound: static or motion b)Type of task: verbal or motor Results and DiscussionWe tested audio spatial localization for horizontal and vertical dimensions in sighted humans taking into consideration both the type of sound (static or motion) and the type of response requested by the task (verbal or motor). In audio spatial localization, sighted humans show enhanced sensitivity for the horizontal dimension, irrespective of the type of sound and the type of task. The static sound condition tend to be easier than the sound motion condition and motor responses more accurate than verbal responses. Developmental improvement between 10-15 years of age. Future direction: since vision has a predominant role in the maturation of space cognition in the brain, we aim to assess the development of audio spatial localization for horizontal and vertical dimensions in blind humans.

Functional evaluation of auditory cortex by functional magnetic resonance before cochlear implantation: a pilot study

To investigate the functional evaluation of auditory cortex by functional magnetic resonance imaging (fMRI) before cochlear implantation (CI). Twenty-one children with severe to profound sensorineural hearing loss (SNHL) (7 cases with normal inner ear structure, 3 cases with large vestibular aqueduct syndrome, 1 case with cochlear nerve hypoplasia) and 7 children with normal hearing were examined by fMRI under sedation. The subjects received acoustic stimuli at four random frequencies (500, 1 000, 2 000, 4 000 Hz) during fMRI examination. Tones were interleaved with silence in a block-periodic fMRI design with 16-second on-off intervals.Each stimulus repeated twice and the total acquisition time was 4 minutes and 28 seconds. Activation was identified in the auditory cortex of the 28 subjects in response to monaural and binaural acoustic stimulation, which was shown in the transverse temporal gyrus (Heschl gyrus), the thalamus and both.Of the 21 patients with SNHL, contralateral dominance was shown in six cases, ipsilateral dominance in five cases and bilateral equilibrium in 10 cases when one ear was exposed to the stimuli. Of the seven children with normal hearing, contralateral dominance was shown in three cases, ipsilateral dominance in two cases and bilateral equilibrium in two cases.No significant difference of the activation intensity in auditory cortex was shown between children with SNHL and normal hearing (P > 0.05). Good hearing recovery was obtained in the 21 patients after CI. No significant difference in the level of hearing and speech rehabilitation was shown between children with LVAS and with normal inner ear structure.Listening behavior response threshold was 55 dBHL in the case with cochlear nerve hypoplasia 10 months after CI. fMRI would be a feasible means of evaluating the function of the auditory cortex, which can be used for assessing the function of the entire auditory system prior to CI combined with ABR and imaging.

Clinical analysis of bilateral same-day myringoplasty for 22 cases with bilateral tympanic membrane perforation

To investigate the feasibility of bilateral same-day myringoplasty and the indications for myringoplasty for patients with bilateral tympanic membrane perforation, and to summarize relevant experience. Twenty-two patients underwent bilateral same-day underlay myringoplasty, and all cases were consistent with the indications for myringoplasty. The preoperative hearing and postoperative hearing at three months were compared, and the postoperative symptoms and complications were observed. Forty patients underwent monaural myringoplasty as the control group over the same period. All cases were followed up for 1 - 3 years. The postoperative hearing was increased by an average of 18 dB, and the rate of closure of tympanic membrane perforation was 93.2% (41/44). There were seven patients with ear fullness after operation in the bilateral myringoplasty group and two patients in the control group (χ(2) = 4.5374, P = 0.0332). There were no differences in the postoperative hearing improvement, the rate of closure and the rates of other discomfort symptoms except for ear fullness between the two groups (P > 0.05). It was feasible and safe to perform bilateral same-day myringoplasty for bilateral tympanic membrane perforation, but the postoperative temporary discomfort of bilateral ear fullness should be informed the patients in advance.

The invention and evolution of the stethoscope

There is a record of direct auscultation in the Hippocratic Corpus and this auscultation method has been used for more than 2000 years. In 1816, the first monaural stethoscope was invented by a French physician Dr. Rene Laennec, who also wrote books introducing how to use the stethoscope and auscultation. This instrument has been improved by several doctors and in 1851,the one improved by George Cammann, an American doctor, was the model of today's stethoscope. The electrical stethoscope was produced by the 3M(TM) Littmann Company in 1999, after which the audio files could be saved. In 2000, the vibration response imaging system was introduced into medicine. In 2006, a noise-free active stethoscope was displayed in the Acoustics Conference held in Honolulu, USA. This kind of stethoscope could be used in noisy or bumpy circumstances. These new pieces of equipment made the stethoscope's application field even broader.

Test-retest reliability of p13n23 and n34p44 components of vestibular evoked myogenic potentials in a large healthy population.

The aim of this study is to evaluate the reliability of the VEMP characteristics recorded in a large number of healthy subjects. VEMP response was obtained on 75 healthy volunteers. Thirty-nine (39) of them were males and 36 were females. Their age varied between 25 and 63 years (mean value 43). Recording was achieved using monaural acoustic stimulation and ipsilateral muscle contraction. Latencies of p13, n23, n34, p44 peaks, p13n23 and n34p44 amplitudes and the interaural amplitude differences (IAD) were assessed. The stability of latencies, amplitudes of the first p12-n23 and second n34-p44 waveforms was verified. The second complex was present in 76%. No factor indicates statistically significant side difference for both runs. IAD variable was not statistically different from zero in all cases. Results show very good reliability for amplitudes, good for some latencies, poor for some other latencies and IAD34-44 and very poor for IAD13-23. No strong and significant correlations were also found between IAD34-44 and IAD13-23 and between p13n23 and n34p44 amplitudes. It is the first time that optimal latencies and amplitudes for early and late components of VEMP are described in a large sample of healthy subjects. The p13, n23, n34 and p44 latencies and p13-n23, and n34-p44 amplitudes were reliable, verifying that the method is reproducible and feasible. The IAD13-23 has the disadvantage of low reliability.

Efectos de la estimulación monoaural y binaural sobre la respuesta evocada auditiva de latencia media

Middle latency evoked potentials include a series of evoked responses which encompass/include myogenic potentials (which translate the existence of sonomotor reflexes), and others which are clearly of neurogenic origin. The latter are the most useful from the clinical point of view. To evaluate the effects of monoaural (MA) and binaural (BA) stimulation on middle latency auditory evoked potentials. We studied 15 healthy people, aged between 18 and 52 years, in whom Cz recording electrodes had been fitted to both short-circuited external ears with Fpz as earth. The stimuli used were alternate clicks of condensation and rarefication of 90 dBHL, first BA and them MA. The auditory evoked response from the brain stem was also recorded. We found more stability of most of the components evaluated during biauricular stimulation. All subjects had Pa waves and 93% had Pb waves. Statistically significant differences were only found for the amplitude of Po and Pa (BA against RE) (Wilcoxon test, p < 0.05). The use of BA stimulation to obtain middle latency evoked potentials is more useful for study of the more rostral parts of the auditory path, since its components are more stable.

A Monaural Stethoscope for Anesthesiologists

A Monaural Stethoscope for Anesthesiologists

Monaural loudness functions under masking.

Monaural loudness functions under masking.

Monaural loudness balance-test and determination of recruitment-degree with short sound-impulses.

(1953). Monaural Loudness-Balance-Test and Determination of Recruitment-Degree with Short Sound-Impulses. Acta Oto-Laryngologica: Vol. 43, No. 6, pp. 573-595.