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，将头盔转换为用户的沉浸式扬声器。Hearshot目前面临着一个具体的双重挑战。一方面，从驾驶员到用户耳朵的声音传输要求更高，以降低功耗并确保声音足够大。另一方面，由于头盔用作扬声器，因此存在对头盔外部的减少的声音传输的明显矛盾的需要，以便减少对附近人的烦扰。除了烦恼之外，减少外部声辐射的挑战还涉及增强的隐私、亲密度和安全性。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视图。将更具体地研究的设计参数是驾驶员和头盔之间的材料连接或特殊处理。该研究项目将包括理论和实验研究，重点是频率响应测量和比较。首先，将完成驱动程序本身的表征。其次，将进行头盔响应和相关声辐射的数值模拟。第三，将使用最先进的声学仪器完成实验调查。这些实验将结合联合收割机两个系统。首先，一个双耳人体模型，以捕捉在用户的耳朵与完整的头部和躯干模拟声压。其次，在消声室中实现了多传声器对外声辐射的测量和空间可视化。作为交付成果，报告和解释将交付给工业合作伙伴，以改善Domio的设计。在利益方面，这将有助于提高Hearshot在体育和军事应用的可穿戴音频设备中的领导地位。预计这第一个项目将导致进一步研究和开发的长期合作。

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.