Acoustic context effects in speech perception

Abstract

The extreme acoustic variability of speech is well established, which makes the proficiency of human speech perception all the more impressive. Speech perception, like perception in any modality, is relative to context, and this provides a means to normalize the acoustic variability in the speech signal. Acoustic context effects in speech perception have been widely documented, but a clear understanding of how these effects relate to each other across stimuli, timescales, and acoustic domains is lacking. Here we review the influences that spectral context, temporal context, and spectrotemporal context have on speech perception. Studies are organized in terms of whether the context precedes the target (forward effects) or follows it (backward effects), and whether the context is adjacent to the target (proximal) or temporally removed from it (distal). Special cases where proximal and distal contexts have competing influences on perception are also considered. Across studies, a common theme emerges: acoustic differences between contexts and targets are perceptually magnified, producing contrast effects that facilitate perception of target sounds and words. This indicates enhanced sensitivity to changes in the acoustic environment, which maximizes the amount of potential information that can be transmitted to the perceiver. This article is categorized under: Linguistics > Language in Mind and Brain Psychology > Perception and Psychophysics

Temporal contrast effects in human speech perception are immune to selective attention

“…This acoustic context effect induced by the surrounding speech rate, known as a temporal contrast effect or rate normalization, has been shown to influence a wide range of different duration-based phonological cues such as voice onset time (VOT; 11,12 ), formant transition duration 13 , vowel duration 14,15 , lexical stress 16 , and word segmentation 17,18 . In fact, a similar contrastive effect is found in the spectral domain: a sentence with a relatively low first formant (F1) can bias the perception of a following target with an ambiguous F1 (e.g., ambiguous between "bit" and "bet") towards a high F1 percept ("bet"; known as a spectral contrast effect or spectral normalization 6,19,20 ).…”

Natural music context biases musical instrument categorization

“…The challenge of rampant stimulus variability is lessened by emphasizing differences between stimuli, which highlights new information that can inform adaptive behavior (Kluender & Alexander, 2007). Perception of speech and nonspeech sounds is widely influenced by spectral contrast effects (SCEs; e.g., Christman, 1954;Kingston et al, 2014;Ladefoged & Broadbent, 1957;Stilp et al, 2010;Stilp et al, 2015; for reviews, see Kluender et al, 2003;Stilp, 2019b). These demonstrations generally used highly acoustically controlled stimuli, which affords good experimental control, but does not necessarily model the acoustic variability present in everyday perception.…”

“…For example, when context sounds are spectrally similar to /o/ (higher frequency first formant), listeners are more likely to categorize the subsequent target vowel as /u/ (lower frequency first formant) and vice versa. SCEs have been repeatedly shown to influence speech perception (e.g., Holt, 2006;Ladefoged & Broadbent, 1957;Sjerps, Zhang, & Peng, 2018;Stilp, 2019b;Stilp, Anderson, & Winn, 2015;Watkins, 1991). This influence extends to perception of other complex sounds such as musical instruments (Stilp, Alexander, Kiefte, & Kluender, 2010).…”

“…Contrast effects play a significant role in speech perception (for reviews, see Kluender, Coady, & Kiefte, 2003;Stilp, 2019b). When spectral properties differ between earlier (context) and later (target) sounds, this can produce spectral contrast effects (SCEs) that bias categorization of later sounds.…”

Wolfgang R. von Kempelen, Le Mécanisme de la Parole, Suivi de la Description d’une Machine Parlante . Vienne, ed. Bauer, 1791

“…Many experimental studies have found that words in the context of the sentence have been identified better than words in isolation. For a detailed discussion on the subject see, among others, Mullennix & Pisoni (2014) or Stilp (2019). "l'I me paroissoit toujours beaucoup plus aigu que l'O ou l'OU" (p. 407).…”