The use of the Lombard Effect in Improving Alaryngeal Speech

In this paper, with the aim of assessing the deterioration of speech intelligibility caused by a speaker wearing a mask, different face masks (surgical masks, FFP2 mask, homemade textile-based protection and two kinds of plastic shields) are compared in terms of their acoustic filtering effect, measured by placing the mask on an artificial head/mouth simulator. For investigating the additional effects on the speaker’s vocal output, speech was also recorded while people were reading a text when wearing a mask, and without a mask. In order to discriminate between effects of acoustic filtering by the mask and mask-induced effects of vocal output changes, the latter was monitored by measuring vibrations at the suprasternal notch, using an attached accelerometer. It was found that when wearing a mask, people tend to slightly increase their voice level, while when wearing plastic face shield, they reduce their vocal power. Unlike the Lombard effect, no significant change was found in the spectral content. All face mask and face shields attenuate frequencies above 1–2 kHz. In addition, plastic shields also increase frequency components to around 800 Hz, due to resonances occurring between the face and the shield. Finally, special attention was given to the Slavic languages, in particular Slovak, which contain a large variety of sibilants. Male and female speech, as well as texts with and without sibilants, was compared.

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Speakers exhibit a multimodal Lombard effect in noise

Scientific Reports ◽

10.1038/s41598-021-95791-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

James Trujillo ◽

Asli Özyürek ◽

Judith Holler ◽

Linda Drijvers

Keyword(s):

Motion Capture ◽

Natural Environment ◽

Language Use ◽

Human Language ◽

Visual Channel ◽

Lombard Effect ◽

Face To Face ◽

Acoustic Analyses ◽

Acoustic Modulation ◽

Action Verbs

AbstractIn everyday conversation, we are often challenged with communicating in non-ideal settings, such as in noise. Increased speech intensity and larger mouth movements are used to overcome noise in constrained settings (the Lombard effect). How we adapt to noise in face-to-face interaction, the natural environment of human language use, where manual gestures are ubiquitous, is currently unknown. We asked Dutch adults to wear headphones with varying levels of multi-talker babble while attempting to communicate action verbs to one another. Using quantitative motion capture and acoustic analyses, we found that (1) noise is associated with increased speech intensity and enhanced gesture kinematics and mouth movements, and (2) acoustic modulation only occurs when gestures are not present, while kinematic modulation occurs regardless of co-occurring speech. Thus, in face-to-face encounters the Lombard effect is not constrained to speech but is a multimodal phenomenon where the visual channel carries most of the communicative burden.

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Vocal plasticity in a reptile

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0451 ◽

2017 ◽

Vol 284 (1855) ◽

pp. 20170451 ◽

Cited By ~ 13

Author(s):

Henrik Brumm ◽

Sue Anne Zollinger

Keyword(s):

Signal Detection ◽

Communication Systems ◽

Vocal Communication ◽

Animal Communication ◽

High Amplitude ◽

Vocal Plasticity ◽

Lombard Effect ◽

Gekko Gecko ◽

High Degree ◽

Signalling Systems

Sophisticated vocal communication systems of birds and mammals, including human speech, are characterized by a high degree of plasticity in which signals are individually adjusted in response to changes in the environment. Here, we present, to our knowledge, the first evidence for vocal plasticity in a reptile. Like birds and mammals, tokay geckos ( Gekko gecko ) increased the duration of brief call notes in the presence of broadcast noise compared to quiet conditions, a behaviour that facilitates signal detection by receivers. By contrast, they did not adjust the amplitudes of their call syllables in noise (the Lombard effect), which is in line with the hypothesis that the Lombard effect has evolved independently in birds and mammals. However, the geckos used a different strategy to increase signal-to-noise ratios: instead of increasing the amplitude of a given call type when exposed to noise, the subjects produced more high-amplitude syllable types from their repertoire. Our findings demonstrate that reptile vocalizations are much more flexible than previously thought, including elaborate vocal plasticity that is also important for the complex signalling systems of birds and mammals. We suggest that signal detection constraints are one of the major forces driving the evolution of animal communication systems across different taxa.

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