Digital Signal Processing and System Theory

Talk Lukas Goßmann


Development of an Autonomous Lombard Speaker

Date: 15.08.2013, 13:30 h - 14:30 h
Room: Aquarium

Lukas Goßmann
CAU, Kiel, Germany,


The characteristics of human speech signals (e.g., speech l evel or pitch frequency) are highly dependent on the environment of the speaker. When a speaking person is located in an environment with a high background noise, she/ he will start to change these characteristics in order to reach better intelligibi lity. The task of speech processing systems comprises, for example, noise suppression or the improvement of speech intelligibility in general. For this reason, these systems often operate in noisy environments, in which also the mentioned Lombard effect is developed by hu- man beings. In order to optimize or evaluate such speech processing systems, it is reasonable to excite the system always with reproducible noise and speech signals. As a reproducible noise scenario is already available in our audio lab, the aim of this thesis is to create an au- tonomous Lombard speaker using an artificial head with integrated ear microphones and mouth loudspeaker. In a first step, the present noise scenario should be estimated. Based on this estimati- on, the corresponding speech signal is selected and reprodu ced in an appropriate way. For this purpose it is necessary to collect speech and noise d ata for comparison and to develop an algorithm within the Kiel Real-Time Audio Tool kit (KiRAT) using the programming language C. Further enhancement of the Lombard speaker could be to use artificial speech which is adapted with regard to the Lombard effect. For this purpose it is necessary to analyze the characteristics of the Lombard e ffect and apply these in an appropriate way to the artificial speech sign.