Development of a corpus of Mandarin sentences in babble with homogeneity optimized via psychometric evaluation

Abstract

Objective: To develop a corpus of sentences in babble noise that is suitable for Mandarin-speaking children. Two experiments were conducted with specific aims of (1) developing sentence material that is grammatically and semantically within the linguistic abilities of children; and (2) improving the efficiency of the test by equalizing the relative intelligibility of individual items in sentences. Design and Study sample: Sentences were extracted from spoken material of Chinese children aged between 4 and 5 years of age. The sentences were tested for intelligibility in a four-talker babble by 96 adult native speakers of Mandarin. Psychometric functions were generated, and used for adjusting signal-to-noise ratios of individual items by varying the level of the time-locked babble to equate intelligibility of the target speech. These adjusted stimuli were tested for intelligibility using a different group of 64 adult listeners. Results: The signal-to-noise ratio for 50% correct was not different before and after adjustments (− 6.1 dB and − 6.0 dB, respectively). However, there was a significant reduction in standard deviation from 2.3 dB before adjustment to 1.1 dB after adjustment (p < 0.05). Conclusions: The experiments established a corpus of Mandarin BKB-like sentences with four-talker babble as competing noise, in which the test items’ homogeneity was optimized via psychometric evaluation (HOPE).

Key Words::

• Speech perception
• psychoacoustics/hearing science
• noise
• pediatric

Acknowledgements

The work was supported in part by the Key Technologies R&D Program of the Ministry of Science and Technology of the People's Republic of China under Grant 2008BA150B01, 2008BA150B08. Cochlear Ltd, Sydney, Australia, in part sponsored this work. The authors are grateful to the following for their assistance in creation of the sentence materials and data collection: Sha Liu, Li-Zhi Zou, Xue-Bin Zhao, Li-Xuan Shi, Jian-Hua Zou, Philip Newall, Emma Van Wanrooy, and Sharon Cameron. Technical assistance was provided by Ai-Jun Li, Jian-Hua Tao, Chris Callaghan, and Jorge Mejia. We would also like to thank Yong-Bin Shi, Kevin Yuen, and Guo-Ping Li for their comments on an earlier version of this manuscript. This project was supported by the HEARing Cooperative Research Centre in Australia.

Declaration of interest: The first author is the sole provider of the recorded test material described in this paper. The authors alone are responsible for the content and writing of the paper.