Wide-bandwidth open canal hearing aid for better multitalker speech understanding

描述(申请人提供)：我们的目标是设计和建造一种新的助听器系统，以减轻助听器用户最常见的抱怨。最常被提及的抱怨包括在多人说话的情况下理解语音困难、音质差、不喜欢他们放大的声音，以及声音反馈引起的不想要的口哨声音。目前的努力，但成效有限，使用信号处理方法，而不是更接近地恢复正常的听觉功能。要使这种助听器成为现实，需要三个关键特征，才能将其与传统助听器区分开来。第一种是用直接驱动鼓膜的非声机械输出换能器取代现有的声学换能器。这种传感器被称为耳透镜，它漂浮在鼓膜上的方式类似于收缩透镜漂浮在眼睛上的方式。二是增加助听器的输出带宽。第三种方法是在耳道内放置一个宽频带麦克风，以捕捉耳廓的绕射信号，就像正常耳朵的功能一样。我们的中心假设是，在开放管道配置中，通过麦克风提供放大的宽带声音和方向依赖的耳廓信号的助听器将比传统助听器表现得更好，特别是在有相互竞争的说话者的情况下。在第二阶段SBIR应用中，提出了四个具体目标。所有的助听器都需要一个“频率增益”处方。然而，目前的处方方法仅限于6 kHz以下的频率，并且匹配的标准已被限制为提供可听性和舒适性，而没有考虑保留声音定位线索。为了解决这些问题，将利用响度模型开发一种新的高频试穿处方，并在听力受损的受试者身上进行测试。在具体目标2中，最初的Earlens系统原型将在听力受损的受试者身上进行双边匹配。建议的测量包括：(1)在0.125至10千赫的听力频率下的功能增益；(2)“空间释放掩蔽”，即在对称分离的多个说话者掩蔽者存在的情况下识别目标语音的能力；(3)“更好的耳朵优势”，其中目标和掩蔽者被不对称地布置，使得目标位于比另一个耳朵更近的地方。后两个实验是用耳透镜进行的，配置成只在特定带宽上放大声音，带宽范围从4到10 kHz。对于特定的目标#3，我们寻求建立一个适用于外部临床试验的耳后(BTE)原型--“阿尔法原型”。提出了许多设计更改，包括工业设计、机械设计、用户界面和电缆设计。在具体目标4中，将在全国各地的四个临床地点进行Earlens听力系统的临床试验。临床试验的目标是获得足够的数据，以便在完成本申请中建议的工作后向FDA提交510(K)。在美国的600万助听器用户中，大多数人报告了各种放大问题。我们的目标是设计一种与正常听觉功能更密切相关的高保真开放式助听器，从而为大脑提供关键提示，以便能够分离来自不同方向的声音，从而允许听者选择性地听到并能够从干扰语音中理解所需的语音。作为这一方法的结果，预计对拟议助听器的使用将比目前市场上的助听器更令人满意。

DESCRIPTION (provided by applicant): Our goal is to design and build a new hearing aid system, which mitigates the most common complaints that hearing aid users have. The most frequently cited complaints include difficulty understanding speech in multi-talker situations, poor sound quality, dislike of the sound of their amplified voice, and unwanted whistling sounds caused by acoustic feedback. Current efforts, with limited success, use signal processing methods rather than restoring more closely the normal auditory function. There are three key features needed to make this hearing aid a reality that differentiate it from conventional hearing aids. The first is to replace the current acoustic transducer with a non-acoustic mechanical output transducer that directly actuates the tympanic membrane. This transducer, called the EarLens, floats on the tympanic membrane in a manner similar to the way a contract lens floats on the eye. The second is to increase the output bandwidth of the hearing aid. The third is to place a wide-bandwidth microphone in the ear canal to capture the pinna diffraction cues, in a similar manner to the functioning of a normal ear. Our central hypothesis is that a hearing aid that delivers amplified wide-bandwidth sound and directionally dependent pinna cues with a microphone in an open canal configuration will perform better than conventional hearing aids, especially with the presence of competing talkers. In this phase II SBIR application four specific aims are proposed. All hearing aids require a "frequency-gain" prescription. However, current prescription methods are limited to frequencies below 6 kHz and the criteria for fitting have been limited to providing audibility and comfort with no considerations being made to preserve sound localization cues. To address these issues, a new high- frequency fitting prescription will be developed using a loudness model and tested on hearing-impaired subjects. In Specific Aim # 2, an initial EarLens system prototype will be bilaterally fit on hearing-impaired subjects. Proposed measurements include: (1) functional gain at audiometric frequencies between 0.125 to 10 kHz; (2) "spatial release from masking" or the ability to discern a target speech in the presence of symmetrically separated multi-talker maskers; (3) the "better ear advantage" in which the target and masker are arranged asymmetrically such that the target lies closer to one ear than the other. The latter two experiments are conducted with EarLens configured to only amplify sounds over specific bandwidths, which will range from 4 to 10 kHz. For Specific Aim # 3, we seek to build a behind-the-ear (BTE) prototype suitable for an external clinical trial - the "alpha prototype". A number of design changes including industrial design, mechanical design, user interface, and cable design are proposed. And in Specific Aim #4, a clinical trial of the EarLens hearing system will be conducted at four clinical sites located around the country. The objective of the clinical trial is to obtain sufficient data for a 510(k) submission to the FDA upon completion of the work proposed in this application. Most of the six million hearing aid owners in the US report various amplification problems. Our goal is to design a high fidelity open canal hearing aid that more closely relates to normal auditory function thereby providing the brain with critical cues so that it is able to segregate sounds originating from different directions and thus allow the listener to hear selectively and be able to understand desired speech from interfering speech. As an outcome of this approach, it is expected that there will be greater satisfaction with usage of the proposed hearing aid than those currently on the market.