Audio Playback: Perceptual optimization of sound presentation over spatially distributed loudspeakers

这个项目解决了这个研究单位的一般挑战，开发方法，改善和个性化的声音信号的听众。在第二个资助期，我们将解决研究单元重点关注的所有三个问题：“声音呈现”、“干扰噪音”和“个性化”。在本项目中，我们将重点关注扬声器的声音呈现。在这里，我们将考虑的方法，以适应扬声器的输入信号，如提高语音清晰度时，在一个房间里听混响和干扰噪声源。此外，我们还将考虑到室内声学特性的测量结果，考虑单独优化声音呈现的方法。在第二个资助期内，我们将扩展第一个资助期开始的语音清晰度工作。开发了一种预处理方法，通过最小化由房间混响对干语音信号的听觉掩蔽，成功地提高了受房间混响影响的扬声器上再现的语音的可懂度。在下一个资助期内，我们将扩展这项工作，包括干扰噪音的听觉掩蔽效应，以便我们也可以在有干扰噪音的混响室中提高语音清晰度。在与开发语音清晰度预测模型的TP E合作中，我们将找到优化频谱内容的算法，并在需要时为听力受损的个人听众应用动态压缩。在第一个资助期内，我们还研究了在特定回放室中准确再现录制声场的感知。正如听力测试所示，我们能够适应回放室的各个房间声学特性。在第二个供资期，我们将以三种方式扩大这项工作。首先，它将被扩展到能够用放置在录音室中的收听者位置处的单个录音单元来记录和再现空间分布的声源。这里，将寻求与立体混响再现系统的组合。为了能够优化混响声场的特性，需要研究高保真度立体声系统如何在回放房间中激发混响声场。第二个努力将与以下事实有关：利用当前的优化方法，记录和回放房间特性都被考虑在内。我们想研究是否有可能制作一种单一的记录格式，可以输入到一个回放系统，只有关于回放房间的知识。第三个努力将着眼于使用传统的立体声内容（这是当前的记录标准）作为输入的方法，所提出的再现方法。

This project addresses the general challenge of this Research Unit to develop methods for an improved and individualized presentation of acoustic signals to listeners. In the second funding period we will address all three problems that the Research Unit focusses on, "sound presentation", "interfering noise", and "individualization".In this project we will focus on the sound presentation over loudspeakers. Here we will consider methods to adapt the input signals for loudspeakers such as to enhance the speech intelligibility when listening in a room with reverberation and interfering noise sources. In addition, we will consider methods to individually optimize the sound presentation taking into account measured acoustical properties of the room.In the second funding period we will extend the work on speech intelligibility that was started in the first funding period. A preprocessing method was developed that successfully enhanced the intelligibility of speech reproduced over loudspeakers affected by room-reverberation by minimizing the auditory masking of the dry speech signal by the room reverberation. In the next funding period, we will extend this work by also including the auditory masking effects of interfering noise such that we can also enhance speech intelligibility in a reverberant room with interfenng noise. In collaboration with TP E which is developing speech intelligibility prediction models we will find algorithms that optimize the spectral content and apply dynamics compression if required for an individual listener with hearing impairment.In the first funding period also the perceptually accurate reproduction of a recorded sound field in a specific playback room was investigated. As demonstrated in listening tests, we were able to adapt to the individual room acoustical properties of the playback room. In the second funding period we will extend this work in three manners. First it will be extended to be able to record and reproduce spatially distributed sound sources with a single recording unit that is placed at the listener's position in the recording room. Here a combination with an ambisonics reproduction system will be pursued. It will require to investigate how the ambisonics system excites the reverberant sound field in the playback room in order to be able to optimize the properties of the reverberant sound field.A second effort will be related to the fact that with the current optimization method both the recording and the playback room properties are taken into account. We want to investigate whether it is possible to make a single recording format that can be input to a playback system that only has knowledge about the playback room.A third effort will look at methods to use conventional stereo content (which is the current recording standard) as an input for the proposed reproduction method.