The principal aim of this paper is to present a novel speech transmission system that conveys speech between an actuator in a wearable wristwatch and the ear bone of a user through a finger. If an individual wears a smart watch equipped with an actuator that can play speech sent via communication lines, speech vibrations propagate from the actuator to fingertips through the human tissue and bone. When an individual places his or her finger into their ear, speech conducted through the finger can be registered and heard. While listening to finger-conducted speech, sounds are muffled, significantly degrading the intelligibility of speech. To mitigate this problem, a formant enhancement filter is applied to the speech prior to being fed into the actuator. With this method, the impulse response of human tissue and bones between the fingertips and wrist on which the watch is worn is first estimated to account for speaker-dependent distortion. Based on the estimated impulse response, a gain filter is used to boost the sound spectra, especially within the formant regions, to compensate for frequency distortion prior to speech transmission. On the other hand, since the impulse responses of humans are quite different for each individual, we propose the novel idea of a personalized algorithm that guides users to select an appropriate gain filter, using the $k$-medoids clustering algorithm. Also, when an individual uses the proposed system, speech quality is degraded due to the ambient noise and acoustic echo between the microphone and actuator in the watch. Thus, to reduce background noise and acoustic echo, an integrated acoustic echo and background noise suppression algorithm is employed. Extensive simulations of the proposed system were performed by creating a novel phantom, which mimics the human hand with an aid of an ear simulator. We demonstrate that the proposed system has improved speech quality, when transmitting speech from the wearable wristwatch to a human perceptual organ through the finger.

中文翻译：

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采用手指传导语音传输系统的智能手表

本文的主要目的是提出一种新颖的语音传输系统，该系统通过手指在可穿戴式手表的执行器和用户的耳骨之间传输语音。如果个人佩戴了配备有可以播放通过通信线路发送的语音的致动器的智能手表，则语音振动会从致动器通过人体组织和骨骼传播到指尖。当一个人将他或她的手指放在他们的耳朵中时，通过手指传导的语音可以被记录和听到。在听由手指传导的语音时，声音会被消声，从而大大降低了语音的清晰度。为了减轻这个问题，在将语音中的共振峰增强滤波器输入到执行器之前。用这种方法 首先估计戴表的指尖和腕之间的人体组织和骨骼的脉冲响应，以说明与扬声器相关的失真。基于估计的脉冲响应，使用增益滤波器来增强声谱，尤其是在共振峰区域内的声谱，以补偿语音传输之前的频率失真。另一方面，由于每个人的冲动响应都大不相同，因此我们提出了一种个性化算法的新颖思想，该算法可指导用户使用$ k $ -medoids聚类算法选择合适的增益滤波器。同样，当个人使用建议的系统时，由于麦克风和手表中的执行器之间的环境噪声和声学回声，语音质量也会下降。因此，为了减少背景噪音和回声，采用集成的回声和背景噪声抑制算法。通过创建一个新的幻像对拟议系统进行了广泛的仿真，该幻像在耳模拟器的帮助下模仿了人的手。我们证明，当通过手指将语音从可穿戴式手表传输到人体感知器官时，提出的系统具有改进的语音质量。