Fisher English Training Part 2, Speech

Introduction Fisher English Training Part 2 Speech represents the second half of a collection of conversational telephone speech (CTS) that was created at the LDC during 2003. It contains 5,849 audio files, each one containing a full conversation of up to ten minutes. Additional information regarding the speakers involved, and types of telephones used, can be found in the companion text corpus of transcripts, Fisher English Training Part 2, Transcripts (LDC2005T19). The Fisher telephone conversation collection protocol was created at LDC to address a critical need of developers trying to build robust automatic speech recognition (ASR) systems. Previous collection protocols, such as CALLFRIEND and Switchboard-II and the resulting corpora, have been adapted for ASR research but were in fact developed for language and speaker identification respectively. Although the CALLHOME protocol and corpora were developed to support ASR technology, they feature small numbers of speakers making telephone calls of relatively long duration with narrow vocabulary across the collection. CALLHOME conversations are challengingly natural and intimate. Under the Fisher protocol, a very large number of participants each make a few calls of short duration speaking to other participants, whom they typically do not know, about assigned topics. This maximizes inter-speaker variation and vocabulary breath while also increasing the formality. Previous protocols such as CALLHOME, CALLFRIEND and Switchboard relied upon participant activity to drive the collection. Fisher is unique in being platform driven rather than participant driven. Participants who wish to initiate a call may do so; however the collection platform initiates the majority of calls. Participants need only answer their phones at the times they specified when registering for the study. To encourage a broad range of vocabulary, Fisher participants are asked to speak on an assigned topic which is selected at random from a list, which changes every 24 hours and which is assigned to all subjects paired on that day. Some topics are inherited or refined from previous Switchboard studies while others were developed specifically for the Fisher protocol. Data The first half of the collection (Fisher English Training Speech Part 1) was released by the LDC in 2004 (LDC2004S13 for speech data, LDC2004T19 for transcripts). Taken as a whole, the two parts comprise 11,699 recorded telephone conversations. The individual audio files are presented in NIST SPHERE format, and contain two-channel mu-law sample data; "shorten" compression has been applied to all files. Data collection and transcription were sponsored by DARPA and the U.S. Department of Defense, as part of the EARS project for research and development in automatic speech recognition. Samples For an example of this corpus, please examine this audio sample. © 2003-2005 Trustees of the University of Pennsylvania

引言
Fisher英语训练语音数据集第二部分为2003年由语言数据联盟（Linguistic Data Consortium, LDC）制作的对话电话语音（Conversational Telephone Speech, CTS）合集的后半部分。该数据集包含5849条音频文件，每条音频对应一段时长不超过10分钟的完整对话。有关参与对话的说话人及所用电话类型的补充信息，可查阅配套的转写文本语料库《Fisher英语训练第二部分 转写文本》（LDC2005T19）。

Fisher电话对话采集协议由LDC开发，旨在满足研发鲁棒性自动语音识别（Automatic Speech Recognition, ASR）系统的开发者的核心需求。此前的采集协议如CALLFRIEND、Switchboard-II及其对应的语料库虽已适配ASR研究，但实际上分别是为语言识别和说话人识别开发的。尽管CALLHOME协议及语料库是为支撑ASR技术开发的，但该数据集的特点是参与说话人数量较少，对话时长相对较长，且整体词汇覆盖范围较窄。CALLHOME的对话极具自然性与私密性，对模型训练而言颇具挑战。

在Fisher协议框架下，大量参与者各自进行数次短时长通话，通话对象通常为互不相识的其他参与者，对话主题为指定内容。此举最大化了说话人间的差异与词汇覆盖广度，同时提升了对话的正式程度。此前的CALLHOME、CALLFRIEND及Switchboard等协议均依赖参与者主动发起活动来推动数据采集，而Fisher协议的独特之处在于，其采用平台驱动而非参与者驱动的采集模式。虽允许有发起通话意愿的参与者自行发起通话，但绝大多数通话均由采集平台主动发起，参与者仅需在注册研究时指定的时段接听电话即可。

为覆盖更广泛的词汇范围，Fisher数据集要求参与者就指定主题进行对话：主题从每日更新的随机主题列表中选取，并分配给当日所有配对的受试者。部分主题沿用或优化自此前的Switchboard研究，其余主题则专为Fisher协议开发。

数据说明
本合集的前半部分（Fisher英语训练语音第一部分）已于2004年由LDC发布（语音数据对应编号LDC2004S13，转写文本对应编号LDC2004T19）。两部分合集整体包含11699条录制的电话对话。单条音频文件采用NIST SPHERE格式封装，包含双声道μ律采样数据；所有文件均应用了"shorten"压缩算法。

本数据集的采集与转写由美国国防高级研究计划局（Defense Advanced Research Projects Agency, DARPA）与美国国防部资助，属于自动语音识别研发的EARS项目的一部分。

样本示例
如需查看本语料库的示例，请查阅该音频样本。

© 2003-2005 宾夕法尼亚大学托管会

搜集汇总

背景与挑战

背景概述

Fisher English Training Part 2, Speech是一个包含975小时英语电话对话语音的数据集，共计5,849个音频文件，用于自动语音识别研究。该数据集是Fisher英语电话对话集合的第二部分，与第一部分一起共包含约1,960小时的对话数据。