Blind Processing for Better Speech Recognition with Cochlear Implant Devices

描述（由申请人提供）：自从大约20年前听觉假体首次广泛使用以来，耳蜗植入技术一直在快速发展。如今，人工耳蜗装置可以保证即使是深度失聪的人也能享受听觉。尽管如此，在包括即使是低水平的背景噪声的条件下，耳蜗植入物通常被证明效果要差得多。在这样的环境中，植入物使用者在理解语音方面有很大的困难。双侧人工耳蜗植入似乎能够通过显著改善双耳听觉线索的获取来在一定程度上改善这种情况。尽管目前的临床数据证明了单侧刺激的实质性受益，但许多植入用户在背景噪声中通信时仍然遇到困难。该研究旨在通过使用一种新的语音处理策略（称为盲信号分离（BSS））来提高噪声场景中的语音理解。BSS是一种统计信号处理技术，可以以揭示其个体（和原始）形式的方式处理不可访问的信号（源）集合的多感官观察。更重要的是，它可以这样做，而无需假设任何关于混合结构或源信号本身的先验知识。BSS仅依赖于两个麦克风的存在，因此可以应用于双侧配置（每只耳朵一个麦克风）或单侧植入设备（每只耳朵两个麦克风）。在这两种配置中，BSS可以有效地利用存在于由两个麦克风接收的信号的混合中的空间线索，并且基本上使用该信息来在空间上将目标与掩蔽信号分离。工作假设是，在空间上分离的目标语音信号从掩蔽源通过诉诸BSS，听众可以受益于语音识别性能的大幅增加时，他们的日常策略相比。拟议的研究将集中于全面评估BSS作为双侧和单侧人工耳蜗植入用户的商业上可行的预处理技术的潜力。我们的假设将在消声和中度至重度混响环境中进行测试。 将对（A）二十（20）名听力正常的年轻成年人使用人工耳蜗处理进行单词识别测试，（B）十（10）名舌后聋成人，使用SPrint或ESPrit 3G声音处理器双耳安装Nucleus 24 R植入装置，以及（C）10名舌后发音的成年人使用采用BEAM策略的Freedom声音处理器单耳佩戴Nucleus 24 R设备。 公共卫生相关性：耳蜗植入物可以部分恢复正常听力的优势，并保证即使是深度耳聋的人也能享受听觉。然而，当噪音存在时，它们的效果较差。这项调查的目的是提高语音识别在嘈杂的环境中，通过使用一种新的语音处理策略，非常适合单侧和双侧人工耳蜗植入用户。

DESCRIPTION (provided by applicant): Cochlear implant technology has developed consistently and rapidly, since auditory prostheses first came into widespread use about twenty years ago. Nowadays, cochlear implant devices can guarantee that even profoundly deaf people can enjoy hearing sensation. Nonetheless, in conditions that include background noise even at low levels, cochlear implants have generally proven much less effective. In such settings implant users have great difficulty understanding speech. Bilateral cochlear implants seem capable of somewhat ameliorating this situation by considerably improving access to binaural auditory cues. Although current clinical data attest to substantial benefits over unilateral stimulation, many implanted users still experience difficulties while communicating in background noise. The proposed investigation aims to boost speech understanding in noisy scenarios, by using a novel speech processing strategy, known as blind signal separation (BSS). BSS is a statistical signal processing technique that can process multi-sensory observations of an inaccessible set of signals (sources) in a manner that reveals their individual (and original) form. More importantly, it can do so without assuming any prior knowledge regarding the mixing structure or the source signals themselves. BSS relies solely on the existence of two microphones and can therefore be applied to either a bilateral configuration (one microphone per ear) or a unilateral implant device (two microphones per ear). In both configurations, BSS can efficiently capitalize on the spatial cues being present in the mixtures of the signals received by the two microphones, and essentially use that information to spatially separate the target from the masker signals. The working hypothesis is that upon spatially segregating the target speech signal from the masker source by resorting to BSS, listeners can benefit from a substantial increase in speech recognition performance when compared to their daily strategy. The proposed study will focus on thoroughly assessing the potential of BSS as a commercially viable pre-processing technique in both bilateral and unilateral cochlear implant users. Our hypothesis will be tested within both anechoic and modest-to-severe reverberant settings. Word recognition tests will be conducted with (A) twenty (20) normal-hearing young adults using cochlear implant processing, (B) ten (10) postlingually deafened adults fitted binaurally with Nucleus 24 R implant devices using either the SPrint or ESPrit 3G sound processor and also (C) ten postlingually deafened adults fitted monaurally with a Nucleus 24 R device using the Freedom sound processor employing the BEAM strategy. Public Health Relevance: Cochlear implants can partially restore the advantages of normal hearing and guarantee that even profoundly deaf people can enjoy hearing sensation. Nonetheless, they are less effective when noise is present. This investigation aims to improve speech recognition in noisy settings, by using a novel speech processing strategy, ideally suited to both unilateral and bilateral cochlear implant users.