June 2021 - Kommunikationstechnik-Kolloquium

Communication Technology Colloquium at IKS
by Irina Ronkartz 16 Jun '21

16 Jun '21

Dear subscribers of the colloquium newsletter, we are pleased to announce the next date of our Communication Technology Colloquium: *Wednesday, June 23, 2021* *Speaker:* Markus Tilichi *Tim*e: 11:00 a.m. *Location*: https://rwth.zoom.us/j/97904157921?pwd=SWpsbDl0MWhrWjY1ZkZaeFRoYmErZz09 Meeting-ID: 979 0415 7921 Passwort: 481650 *Master-Lecture*: Enhanced Own Voice Perception for Hearables Using Machine Learning Modern headphones implement sophisticated signal processing and control algorithms to improve the user’s hearing and listening experience. Especially new generation in-ear headphones, so-called hearables, integrate these technologies, such as active noise control, on a large scale. A remaining issue with hearables is the sound degradation introduced through sealing the ear canal. This degradation is called the Occlusion Effect. It is often described as boomy and hollow perception of the speaker’s own voice. While Active Noise Cancellation reduces ambient noise, the Occlusion Effect still persists. In order to improve the speaker’s own voice perception and alleviate the Occlusion Effect, it is required to play back some of the voice signal without amplifying ambient noise. In this thesis a novel approach for selective hear-through based on deep neural networks is investigated. Integrated into a feed-forward ANC topology the proposed neural network utilizes ambient and in-ear microphone signals for an estimation of the speaker’s own voice. Speech samples for both microphone signals were simulated through augmentation of the DARPA TIMIT speech corpus. This included virtually occluding the samples for one channel and adding real-world noise samples to the other. The proposed network was found to reduce ambient noise from the test dataset to a barely audible extent. Metrics for quality and intelligibility suggest superior denoising performance in comparison with one channel network benchmarks. Despite the relatively small training dataset, the network may also regularize well when trained with measurement data. All interested parties are cordially invited, registration is not required. General information about the colloquium, as well as a current time scale of the Communication Technology Colloquium can be found at: https://www.iks.rwth-aachen.de/atktuelles/kolloquium -- Irina Ronkartz Institute of Communication Systems (IKS) RWTH Aachen University Muffeter Weg 3a, 52074 Aachen, Germany +49 241 80 26958 (phone) ronkartz(a)iks.rwth-aachen.de http://www.iks.rwth-aachen.de/

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Communication Technology Colloquium at IKS
by Irina Ronkartz 14 Jun '21

14 Jun '21

Dear subscribers of the colloquium newsletter, we are pleased to announce the next date of our Communication Technology Colloquium: *Monday, June 21, 2021* *Speaker:* Henning Niendieck *Time:* 2:00 p.m. *Location*: https://rwth.zoom.us/j/97904157921?pwd=SWpsbDl0MWhrWjY1ZkZaeFRoYmErZz09 Meeting-ID: 979 0415 7921 Passwort: 481650 *Master-Lecture*: Optimized Design of an Acoustic Front-End for Active Noise Cancelling Headphones Headphones with active noise cancelling (ANC) capability become more and more common in everyday life. The acoustic front-end, consisting of the headphone enclosure, a speaker and at least two microphones, is a crucial part of the ANC system. It significantly influences the achievable degree of noise cancelling. The optimization of the acoustic front-end is therefore a key factor for a high ANC performance. Being able to completely predict the influence of every element of the acoustic front-end is a desirable goal. This work comprises an investigation of the different components of the acoustic front-end. It includes the characterization of a set of microphones to evaluate the influence on the ANC performance. A development of a model of the electro-acoustic system of a headphone enclosure with an integrated dynamic speaker allows the simulation of relevant transfer paths. Every individual element of the enclosure is modeled, so that the effect of every parameter on the transfer paths can be investigated. This provides a great advantage over investigations on the basis of measurements. A comparison of the boundary element method and lumped element method shows their suitability for acoustic modeling. The inability of the used implementation of the boundary element method to directly model viscothermal losses exhibits limitations, as these losses play an important role in the acoustic front-end. A 3D print of the prototype allowed the verification of the acoustic model with measurements. The different enclosure design parameters with regard to ANC performance were studied on the bases of both, simulations and measurement. An improvement of the prototype could be achieved by damping resonances. This reduces group delay in the path between the speaker and the inner microphone, which is an important limiting factor for ANC. The group delay of the inner microphone was found to be significant for low frequencies. The investigations deliver valuable knowledge about the influence of the different parameters of the acoustic front-end on the important factors for ANC. An acoustic model was obtained that allows the prediction of various transfer paths and an easy fine tuning of the elements of the acoustic front-end. All interested parties are cordially invited, registration is not required. General information about the colloquium, as well as a current time scale of the Communication Technology Colloquium can be found at: https://www.iks.rwth-aachen.de/aktuelles/kolloquium -- Irina Ronkartz Institute of Communication Systems (IKS) RWTH Aachen University Muffeter Weg 3a, 52074 Aachen, Germany +49 241 80 26958 (phone) ronkartz(a)iks.rwth-aachen.de http://www.iks.rwth-aachen.de/

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Communication Technology Colloquium at IKS
by Irina Ronkartz 10 Jun '21

10 Jun '21

Dear subscribers of the colloquium newsletter, we are pleased to announce the next date of our Communication Technology Colloquium: *Thursday, June 17, 2021* *Speaker*: Daniel Gotzens *Time*: 11:00 a.m. *Location*: https://rwth.zoom.us/j/97904157921?pwd=SWpsbDl0MWhrWjY1ZkZaeFRoYmErZz09 Meeting-ID: 979 0415 7921 Passwort: 481650 *Bachelor Lecture*: Real-Time Own Voice Estimation for Hearables Utilizing Multiple Microphone Signals Hearable devices employ several microphones to be used in telecommunication applications as well as for active noice cancellation. It is proposed that the signals generated by these microphones can be combined into an accurate and low-interference estimate of the user's own voice in real time by using digital beamforming algorithms, namely the so-called delay-and-sum and minimum variance distortionless response beamformers, especially in conjunction with additional filtering in the shape of a bandpass or a Wiener filter. To test this, several input samples are recorded on a hearable device and then processed with said algorithms. It is found that it is indeed possible to generate such a signal using the proposed algorithms, improving the signal to noise ratio by several decibels while maintaining a low distortion of the speech signal. All interested parties are cordially invited, registration is not required. General information about the colloquium as well as a current time scale of the Communication Technology Colloquium can be found at: https://www.iks.rwth-aachen.de/aktuelles/kolloquium -- Irina Ronkartz Institute of Communication Systems (IKS) RWTH Aachen University Muffeter Weg 3a, 52074 Aachen, Germany +49 241 80 26958 (phone) ronkartz(a)iks.rwth-aachen.de http://www.iks.rwth-aachen.de/

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