Investigation of sound radiation of the sound transducer Domio for sport helmets

Hearshot的旗舰产品是Domio头盔音频设备：一种用于摩托车、军用或运动头盔的设备。Domio是一个电磁驱动器，将头盔转变为用户的身临其境的扬声器。《心动》目前正面临着一个特殊的双重挑战。一方面，要求司机向用户耳朵传递更高的声音，以降低功耗并确保声音足够响亮。另一方面，由于头盔随后起到扬声器的作用，因此显然需要减少头盔外部的声音传播，以减少对附近居民的烦扰。除了恼人之外，减少外部声音辐射的挑战还涉及到增强隐私、亲密性和安全性。为了应对这些挑战，该项目将调查潜在的振动声学，以提供对所涉及的物理学的清晰看法。将更具体地调查的设计参数是驾驶员和头盔之间的材料连接或特殊处理。本研究项目将包括理论和实验研究，重点是频率响应的测量和比较。首先，将完成对驱动程序本身的描述。其次，将对头盔的响应和相关的声辐射进行数值模拟。第三，将利用尖端的声学仪器完成实验研究。这些实验将结合两个系统。首先，一个双耳人体模型，用来捕捉用户耳朵的声压，并模拟整个头部和躯干。其次，对于外部声辐射的测量和空间可视化，将在电波暗室中实现多麦克风测量。作为可交付成果，报告和解释将交付给工业合作伙伴，以改进Domio的设计。在利益方面，这将有助于增加Hearshot在运动和军事应用的可穿戴音频设备方面的领导地位。预计这第一个项目将为进一步的研究和开发带来长期的合作。

Hearshot' flagship product is the Domio Helmet Audio Device: a device for motorcycle, military or sport helmets. The Domio is an electromagnetic driver to transform the helmet into an immersive loudspeaker for the user. Hearshot is currently facing a specific and dual challenge. On one side, there is a requirement for higher sound transmission from the driver to the user's ears to reduce power consumption and ensure that the sound is loud enough. On the other side, since the helmet then act as a loudspeaker, there is an apparently contradictory need for a reduced sound transmission outside the helmet in order to reduce annoyance for nearby peoples. Besides annoyance, this challenge of reducing the external sound radiation also relates to enhanced privacy, intimacy, and security. In order to address these challenges, this project will investigate the underlying vibroacoustics to provide a clear view on the involved physics. The design parameter that will be more specifically investigated is the material connections or special treatments between the driver and the helmet. This research project will include theoretical and experimental investigations with a focus on frequency responses measurements and comparison. First, a characterization of the driver per se will be completed. Second, numerical simulations of the response of the helmet and related sound radiation will be performed. Third, an experimental investigation will be completed using cutting-edge acoustical instrumentation. These experiments will combine two systems. First, a binaural manikin to capture the sound pressure at the user's ears with full head and torso simulation. Second, for the measure and spatial visualization of external sound radiation multi-microphone measurements will be achieved in anechoic chamber. As deliverable, reports and interpretations will be delivered to the industrial partner in order to ameliorate Domio's design. In terms of benefits, this will contribute to the increase of the leadership of Hearshot in wearable audio devices for sports and military applications. It is also expected that this first project will lead to a long-term collaboration for further research and development.