The effect of vowel lengthening on the intelligibility of occluded Lombard speech

Authors

  • Xinyi Zhang ÉTS
  • Meghan Clayards McGil
  • Rachel Bouserhal ÉTS

Abstract

When speaking in noise, people’s vocal effort is automatically adjusted in order to improve the intelligibility of their speech; this phenomenon is called the Lombard effect. However, when the ear canals are blocked by, for example, hearing protection devices or hearables, the occlusion of the ears causes significant changes in speech production, particularly in noise. The result is a Lombard speech that is less intelligible than its typical form; we refer to this as occluded Lombard speech. The change in speech production is due to the lowered noise levels at the ear canals caused by the passive attenuation of the in-ear devices, as well as a change in the talkers’ perception of their own voice.

One main characteristic of the open-ear Lombard speech is elongated vowels; however, this elongation is much shorter in occluded Lombard speech. This discrepancy leads to our research question: Can elongating the vowels in the occluded Lombard speech improve its intelligibility?

To answer this question, thirteen participants, all native French speakers, listened to seventy-eight sentences of occluded Lombard speech from an open-access database. These sentences were presented to the participants under five signal-to-noise ratios (-3 dB, 0 dB, 5 dB, and 10 dB). Among all these stimuli, half of them had their vowels artificially lengthened. Participants were asked to repeat the sentence and then rate the ease of understanding after listening to each sentence. The number of words correctly repeated and the self-rated ease of understanding are analyzed and presented.

 

Additional Files

Published

2022-08-09

How to Cite

1.
Zhang X, Clayards M, Bouserhal R. The effect of vowel lengthening on the intelligibility of occluded Lombard speech. Canadian Acoustics [Internet]. 2022 Aug. 9 [cited 2024 Nov. 21];50(3):86-7. Available from: https://jcaa.caa-aca.ca/index.php/jcaa/article/view/3884

Issue

Vol. 50 No. 3 (2022)

Section

Proceedings of the Acoustics Week in Canada

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