Waldstein R S, Boothroyd A
Center for Research in Speech and Hearing Sciences, Graduate School, City University of New York, USA.
J Speech Hear Res. 1995 Jun;38(3):690-705. doi: 10.1044/jshr.3803.690.
The benefits of two tactile codes of voice fundamental frequency (F0) were evaluated as supplements to the speechreading of sentences in two short-term training studies, each using 12 adults with normal hearing. In Experiment 1, a multichannel spatiotemporal display of F0, known as Portapitch, was used to stimulate the index finger. In an attempt to improve on past performance with this display, the coding scheme was modified to better cover the F0 range of the talker in the training materials. For Experiment 2, to engage kinesthetic/proprioceptive pathways, a novel single-channel positional display was built, in which F0 was coded as the vertical displacement of a small finger-rest. Input to both displays consisted of synthesized replicas of the F0 contours of the sentences, prepared and perfected off-line. Training with the two tactile F0 displays included auditory presentation of the synthesized F0 contours in conjunction with the tactile patterns on alternate trials. Speechreading enhancement by the two tactile F0 displays was compared to the enhancement provided when auditory F0 information was available in conjunction with the tactile patterns, by auditory presentation of a sinusoidal indication of the presence or absence of voicing, and by a single-channel tactile display of the speech waveform presented to the index finger. Despite the modified coding strategy, the multichannel Portapitch provided a mean tactile speechreading enhancement of 7 percentage points, which was no greater than that found in previous studies. The novel positional F0 display provided only a 4 percentage point enhancement. Neither F0 display was better than the simple single-channel tactile transform of the full speech waveform, which gave a 7 percentage point enhancement effect. Auditory speechreading enhancement effects were 17 percentage points with the voicing indicator and approximately 35 percentage points when the auditory F0 contour was provided in conjunction with the tactile displays. The findings are consistent with the hypothesis that subjects were not taking full advantage of the F0 variation information available in the outputs of the two experimental tactile displays.
在两项短期训练研究中，对两种语音基频（F0）触觉编码作为句子唇读补充的益处进行了评估，每项研究都使用了12名听力正常的成年人。在实验1中，一种称为Portapitch的F0多通道时空显示被用于刺激食指。为了改进过去使用这种显示的表现，对编码方案进行了修改，以便更好地覆盖训练材料中说话者的F0范围。在实验2中，为了激活动觉/本体感觉通路，构建了一种新颖的单通道位置显示，其中F0被编码为一个小手指支撑物的垂直位移。两种显示的输入均由句子F0轮廓的合成复制品组成，这些复制品是离线准备和完善的。使用这两种触觉F0显示进行的训练包括在交替试验中结合触觉模式对合成F0轮廓进行听觉呈现。将这两种触觉F0显示对唇读的增强效果与以下情况进行了比较：当听觉F0信息与触觉模式一起可用时通过听觉呈现正弦波形来指示是否有声，以及通过向食指呈现语音波形的单通道触觉显示。尽管编码策略有所修改，但多通道Portapitch提供的平均触觉唇读增强效果为7个百分点，并不比先前研究中发现的效果更好。新颖的位置F0显示仅提供了4个百分点的增强效果。两种F0显示都不比完整语音波形的简单单通道触觉变换效果好，后者给出了7个百分点的增强效果。有声指示器的听觉唇读增强效果为17个百分点，当听觉F0轮廓与触觉显示一起提供时增强效果约为35个百分点。这些发现与以下假设一致，即受试者没有充分利用两种实验性触觉显示输出中可用的F0变化信息。
