Blind Processing for Better Speech Recognition with Cochlear Implant Devices

描述(申请人提供)：自大约20年前人工耳机首次被广泛使用以来，人工耳蜗技术得到了持续和快速的发展。如今，人工耳蜗植入设备可以保证即使是深度失聪的人也能享受到听觉。尽管如此，在包括背景噪音的条件下，即使是低水平的背景噪音，人工耳蜗植入物通常被证明效果要差得多。在这种情况下，植入者很难理解语音。通过显著改善双耳听觉提示，双侧人工耳蜗术似乎能够在一定程度上改善这种情况。虽然目前的临床数据证明了单侧刺激的实质性好处，但许多植入的使用者在背景噪音中交流时仍然遇到困难。这项拟议的研究旨在通过使用一种新的语音处理策略，即盲信号分离(BSS)来提高噪声场景下的语音理解。盲源分离是一种统计信号处理技术，它可以处理对一组不可访问的信号(源)的多感官观测，以揭示其单独的(和原始的)形式。更重要的是，它可以在不假设关于混合结构或源信号本身的任何先验知识的情况下这样做。BSS完全依赖于两个麦克风的存在，因此可以应用于双侧配置(每耳一个麦克风)或单侧植入装置(每耳两个麦克风)。在这两种配置中，BSS可以有效地利用由两个麦克风接收的信号的混合中存在的空间线索，并且基本上使用该信息来在空间上将目标从掩蔽信号中分离出来。工作假设是，当通过求助于盲源分离目标语音信号与掩蔽源时，与他们的日常策略相比，收听者可以从语音识别性能的显著提高中受益。这项拟议的研究将集中于彻底评估BSS作为一种商业上可行的前处理技术在双侧和单侧人工耳蜗使用者中的潜力。我们的假设将在无回声和中度至重度混响环境中进行测试。将对以下人群进行单词识别测试：(A)二十(20)名使用人工耳蜗处理的正常听力成年人；(二)十(10)名使用SPRINT或ESPRIT 3G声音处理器双耳植入Nucleus 24R植入装置的语言后聋成年人；以及(C)十名使用Freedom声音处理器使用BEAM策略单耳安装Nucleus 24R装置的语言后聋成年人。 公共卫生相关性：人工耳蜗可以部分恢复正常听力的优势，并保证即使是深度失聪的人也能享受听觉。尽管如此，当存在噪音时，它们的效果就不那么好了。这项研究旨在通过使用一种新的语音处理策略来改善噪声环境下的语音识别，该策略非常适合单侧和双侧人工耳蜗者。

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.