Lexical Influences on Auditory Streaming

Abstract

SummaryBiologically salient sounds, including speech, are rarely heard in isolation. Our brains must therefore organize the input arising from multiple sources into separate “streams” and, in the case of speech, map the acoustic components of the target signal onto meaning. These auditory and linguistic processes have traditionally been considered to occur sequentially and are typically studied independently [1, 2]. However, evidence that streaming is modified or reset by attention [3], and that lexical knowledge can affect reports of speech sound identity [4, 5], suggests that higher-level factors may influence perceptual organization. In two experiments, listeners heard sequences of repeated words or acoustically matched nonwords. After several presentations, they reported that the initial /s/ sound in each syllable formed a separate stream; the percept then fluctuated between the streamed and fused states in a bistable manner. In addition to measuring these verbal transformations, we assessed streaming objectively by requiring listeners to detect occasional targets—syllables containing a gap after the initial /s/. Performance was better when streaming caused the syllables preceding the target to transform from words into nonwords, rather than from nonwords into words. Our results show that auditory stream formation is influenced not only by the acoustic properties of speech sounds, but also by higher-level processes involved in recognizing familiar words.

Stream segregation of concurrent speech and the verbal transformation effect: Influence of fundamental frequency and lateralization cues

“…These circumstances typically lead to even more degraded and ambiguous acoustic cues to a spoken message than occur for speech in quiet, owing to energetic and informational masking between voices. The results of the study reported here are in accord with the notion that a comprehensive account of spoken word recognition must involve reciprocal interactions between auditory stream segregation and linguistic knowledge, whereby each affects the other (Billig et al, 2013).…”

“…For general auditory grouping, these factors include attention and switching attention (e.g., Cusack et al, 2004), and the effects of pattern regularity on stream formation and stabilization (e.g., Bendixen et al, 2010;Devergie et al, 2010). For the perceptual organization of speech, additional factors include articulatory constraints (e.g., Basirat et al, 2012) and lexical constraints (e.g., Billig et al, 2013). Listening to speech in the presence of other speech is commonplace and doing so involves concurrent segregation, as in the VTE study reported here.…”

“…Therefore, the VTE is influenced not only by linguistic processes, but also by the cleaving off and regrouping of acousticphonetic elements in a speech stimulus. Since the establishment of this relationship, the VTE has been used as a means of investigating the role of formant transitions and the continuity of the pitch contour in holding together the speech stream (Stachurski, 2012;Stachurski et al, 2015) and of the role of lexical knowledge in the formation of speech streams (Billig et al, 2013). All of the VTE studies considered so far involved presenting listeners with only one repeating stimulus sequence at a time.…”

T'ain't the way you say it, it's what you say – Perceptual continuity of voice and top–down restoration of speech

“…In partial support of this idea, a recent study with sentences involving cochlear implant listeners (Bhargava et al, 2014), extending the study of Miller and Licklider (1950), showed that in some cases strong continuity illusion could be observed without a phonemic restoration effect and that in other cases better phonemic restoration benefit could be observed with lesser continuity illusion. To explain our persistent phonemic restoration effect, we propose that the participants were able to focus on the message, and that the high linguistic context of the sentences enabled participants to overcome the voice discontinuity to create a higher-level reconstructed representation (also supported by Billig et al, 2013;Warren and Sherman, 1974). This implies that, at this slow rate of interruptions, participants would rely on the linguistic context to achieve phonemic restoration and would not be disturbed by the inconsistent indexical cues.…”

Roaring lions and chirruping lemurs: How the brain encodes sound objects in space

“…This perceptual organization is referred to as streaming (Carlyon 2004;Bregman 1990). Auditory streaming is a basic capacity of the auditory system and is influenced by the acoustic cues of the stimulus as well as by higher-level semantic processes (Billig et al 2013). Whereas frequency and timbre are some of the most powerful acoustic cues used for auditory streaming (for reviews see e. g. Darwin 1999;Carlyon 2004;Moore and Gockel 2012), spatial cues can play an important role in auditory stream segregation as well.…”