HEARING LOSS, SPECTRAL DEFICITS AND FORMANT ENHANCEMENT

该项目的总体目标是评估有前途的信号处理技术，以提高语音频谱特性，改善听力困难（HoH）的听众的语音理解。 这些频谱增强包括：1）共振峰间频谱谷的加深，2）语音的频率缩放，以及3）加深和缩放两者的组合。 许多听力障碍（HoH）的听众可以正常地分辨低频频谱线索，但他们通常不太能够分辨高频信号中的频率信息。 在语音中，高频第二共振峰（F2），提供了重要的信息音素的区别，是不容易解决这些HoH听众。 正弦建模技术将用于检测快速变化的音节中的频谱峰值，并加深峰值之间的频谱谷。 声音设计软件将用于实现适度的频率缩放（最多减少30%），同时保持良好的音质。 预计这些组合方案将产生高质量的语音信号，其共振峰更容易被HoH听众分辨。 根据频率辨别和频谱峰值检测任务，将具有中度至重度听力损失的两组听众识别为具有更好或更差的频谱分辨率能力。 然后，这些听众将识别未修改的刺激和已被所提出的处理方案增强的刺激。 结果将证明每个计划单独的好处，并结合计划。 使用飞行员处理刺激的早期结果显示出改善中度至重度听力损失听众的语音感知能力的目标。 从拟议的调查结果将提供重要的额外的试点数据，将作为未来的语音增强调查的基础。 这项研究的一个长期目标是开发可以在可穿戴放大设备中实现的实时增强算法。

The overall goal of this project is to evaluate promising signal processing techniques to enhance speech spectral characteristics for improved speech understanding by hard-of-hearing (HoH) listeners. These spectral enhancements include: 1) deepening of between-formant spectral valleys, 2) frequency scaling of speech, and 3) combinations of both deepening and scaling. Many hard-of- hearing (HoH) listeners can resolve low-frequency spectral cues normally but they are often less able to resolve frequency information in higher-frequency signals. In speech, higher- frequency second formants (F2), which provide important information for phoneme distinctions, are not easily resolved by these HoH listeners. Sinusoidal modeling techniques will be used to detect spectral peaks in rapidly changing syllables, and to deepen spectral valleys between peaks. Sound design software will be used to accomplish modest frequency scaling (up to 30 percent reduction) while retaining good sound quality. It is anticipated that these combined schemes will produce good-quality speech signals with formants that are more easily resolved by HoH listeners. Two groups of listeners with moderate to severe hearing loss will be identified as having better or poorer spectral resolution abilities based on frequency discrimination and spectral peak detection tasks. These listeners will then identify unmodified stimuli and stimuli that have been enhanced by the proposed processing chemes. Results will demonstrate the benefits of each scheme individually, and of the combined schemes. Early results using pilot processed stimulil show promise toward the goal of improving speech perception abilities of listeners with moderate to severe hearing loss. Results from the proposed investigation will provide important additional pilot data that will serve as a basis for future investigations of speech enhancements. A long-term goal of this research is the development of real-time enhancement algorithms that can be implemented into wearable amplification devices.