Two PhD positions at Quality and Usability Lab, Technical University of Berlin, Germany

Two PhD positions at Quality and Usability Lab, Technical University of Berlin, Germany

We are looking to recruit two Doctoral Researchers to join Quality and Usability Lab, at Technical University of Berlin, Germany. Both positions are research assistant positions (TVL-E13) and depending on follow up funding to be continued until doctorate thesis can be finished.

The Quality and Usability Lab is part of TU Berlin’s Faculty IV and deals with the design and evaluation of human-machine interaction, in which aspects of human perception, technical systems and the design of interaction are the subject of our research. We focus on self-determined work in an interdisciplinary and international team; for this we offer open and flexible working conditions that promote scientific and personal exchange and are a prerequisite for excellent results.

1. Research Assistant (full-time) Speech Quality

The research is in the area of the assessment of the quality of speech services using a crowdsourcing approach. The aim of the research is to analyze how crowdsourcing-based listening-only and conversational speech quality evaluation experiments can be set up in order to provide valid and reliable results, and how the characteristics of the test participants, the test environment and the playback system can be assessed in online tests. It will be assessed which differences are to be expected between crowdsourcing and laboratory-based speech quality evaluation, and how these differences influence the development of instrumental speech quality prediction models. The results are expected to influence methods for speech quality assessment in crowdsourcing, as they are summarized in ITU-T Recommendation P.808.

This project is funded by the Deutsche Forschungsgemeinschaft, DFG, and is limited to a duration until January 31, 2024 (compensation TVL E13). A subsequent ongoing employment is supported if the PhD cannot be finished in running time of the project

1. Tasks:

• Interacting and extending web platforms that are created for conducting and managing listening-only or conversational experiments (Frontend: HTML/JS/CSS, backend for conversation testing: Node.js / express.js, WebRTC)

• Conducting subjective listening-only and/or conversation tests in the laboratory and via crowdsourcing; Analyzing the results

• Recording of source speech signals in both laboratory and large-scale crowdsourcing and preparing speech dataset.

• Enhancing test methods (that we developed for ITU-T Rec. P.808) for screening the participants’ ability, environment and set-up suitability for the speech quality assessment tasks.

• Processing speech signals collected in a crowdsourcing approach, and applying relevant artificial network degradation conditions (e.g. background noise, clipping, etc.).

• Benchmarking state-of-the-art instrumental models for predicting speech quality based on their performance on the collected crowdsourcing dataset.

• Project communication and reporting.

• Publication and presentation of project and research results in scientific journals, at conferences, at workshops and ITU-T Study Group 12 expert’s meetings. Publication and presentation of project and research results in scientific journals, at conferences, and in workshops as well as standardization meetings of ITU-T

1. Requirements:

• Successfully completed university degree (Master, Diplom or equivalent) in computer engineering/science, informatics, media informatics, digital media, or information systems (or an equivalent technical background)

• Deep knowledge, and hands-on experience in one or more general purpose programming languages (recommended is Python)

• Profound programming skills in front-end (HTML5/CSS3, JS, jQuery, JSON), AND one scripting language for data processing (either MATLAB, Python or R), and ideally backend development skills

• Knowledge about digital signal processing, beneficial: speech signal processing respectively audio signal processing and acoustics

• Knowledge about empirical subjective tests and statistical data analysis is appreciated

• Language skills: English fluent in writing and speaking (B2 level); willingness to learn German is expected

• Joy of working in an interdisciplinary and international environment

2. Research Assistant (full-time) Conversation Quality – Salary grade E 13 TV-L

The position is open to do research in the field of speech signals analysis, and the assessment of speech quality in different (mobile and fixed) networks. Therefore, speech signals are to be analyzed in listening-only as well as conversational situations in order to get indications or the perceived quality. Based on these analysis, signal-based and parametric models for the estimation of speech quality can be extended and integrated. One focus of the present research may be the evaluation of new speech codecs in different network scenarios. The models are to be validated based on subjective listening and conversation tests.

The initial funding is available from September 1^st, 2022 and is limited until April 30^th, 2023; however, the outcomes of the research should be used to support the preparation of a new project application, and may also become a foundation for a later PhD thesis. A subsequent position as a research assistant from the project funds would be possible if the funds were approved.

2.1 Tasks

• Maintaining and further developing a platform to conduct web-based voice calls

• Conducting subjective conversation tests in the laboratory and via crowdsourcing

• Analysis of speech signals

• Creating and evaluating models for predicting quality aspects using different algorithms (including traditional signal processing methods and state-of-the-art DNNs)

• Project communication and reporting

• Publication and presentation of project and research results in scientific journals, at conferences, and in workshops

2.2. Requirements

• Master or diploma in electrical engineering, computer engineering, computer science, media informatics, media technology, information systems management (or an equivalent technical background)

• Profound knowledge in digital signal processing, beneficial: speech signal processing or audio signal processing, respectively

• Good programming skills (e.g. MATLAB or Python) and safe handling of web development tools (e.g. HTML5/CSS3, JS, ideally also backend development skills)

• Interest in running user studies with test participants to determinate speech quality

• Language skills: English and German fluent in writing and speaking

• Knowledge about empirical studies and statistical data analysis is appreciated

• Joy of working in an interdisciplinary and international environment

Application

For both positions, please send the following documents, bundled in a single PDF file, to Prof. Dr.-Ing. Sebastian Möller bewerbung@qu.tu-berlin.de: Letter of application, curriculum vitae, copies of certificates, job references. Please also specify for which position you are applying.

To ensure equal opportunities between women and men, applications by women with the required qualifications are explicitly desired. Qualified individuals with disabilities will be favored.