HEARING LOSS, SPECTRAL DEFICITS AND FORMANT ENHANCEMENT

这个项目的总体目标是评估有前景的信号处理技术，以增强语音频谱特征，以改善重听(HoH)听者的语音理解。这些频谱增强包括：1)加深共振峰之间的频谱谷，2)语音的频率缩放，以及3)加深和缩放的组合。许多重听(HoH)听者可以正常分辨低频频谱提示，但他们通常较不能分辨高频信号中的频率信息。在语音中，为音素区分提供重要信息的高频第二共振峰(F2)不容易被这些HoH听者解析。正弦建模技术将被用来检测快速变化的音节中的光谱峰值，并加深峰值之间的光谱谷。音响设计软件将被用来完成适度的频率调整(最高可减少30%)，同时保持良好的音质。预计这些组合方案将产生具有共振峰的高质量语音信号，这些共振峰更容易被HoH收听者分辨。根据频率辨别和频谱峰值检测任务，两组中度至重度听力损失的听众将被识别为具有较好或较差的频谱分辨率能力。然后，这些听者将识别未经修改的刺激和已被建议的加工程序增强的刺激。结果将分别展示每项计划和综合计划的好处。使用试点处理的刺激的早期结果显示，对于改善中重度听力损失的听者的言语感知能力的目标是有希望的。拟议的调查结果将提供重要的额外试点数据，这些数据将作为未来语音增强研究的基础。这项研究的一个长期目标是开发可以在可穿戴式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.