About

Daniel Swingley is a Professor in the Department of Psychology at the University of Pennsylvania. His research focuses on developmental psychology, specifically on language and communication, memory and learning, and perception. His work investigates word recognition, word learning, and lexical representation in infants and young children, employing perceptual experiments, statistical and acoustic analyses of infant-directed speech, and perceptual learning studies of adults. Swingley's approach combines cognitive science and engineering to understand early language acquisition, exploring how children interpret their language environment and how this leads to successful learning during development. He teaches courses such as Introduction to Psychology, Cognitive Development, and a Proseminar in Cognitive Development. Swingley is actively involved in advising graduate students and considers new students for admission for Fall 2026. His contributions include significant research on how infants learn speech sounds and word forms, the influence of phonological variation, and the process of lexical learning, with numerous publications in reputable scientific journals.

Research topics

• Psychology
• Linguistics
• Computer science
• Cognitive psychology
• Natural language processing

Selected publications

• Measuring young children’s recognition of phonetically reduced word forms using story-guided looking

  OSF Preprints (OSF Preprints) · 2026-03-04

  otherSenior author

  Infants readily recognize a variety of words when tested in the lab: e.g., when presented with a picture of a ball and a shoe, they look longer at the ball after hearing “Look at the ball!” (e.g., Fernald et al., 1998). This study develops a variant of this method to assess word recognition, embedding a standard fixation procedure (measuring children’s looking to one of two pictures given a sentence that aligns with only one of them) within the discourse context of a story. Inspired by work by Scott et al. (2012), who used a similar method to investigate theory-of-mind, we will present children with sequential sentences of a coherent story while two scenes are displayed visually, one matching the spoken sentence and one not. This new story-guided looking method provides a felicitous context to investigate children's response to properties of normal, conversational speech. In particular, we will examine young children’s understanding of reduced pronunciation variants. Reduction phenomena are pervasive in normal speech: Whole speech sounds can be dropped or added, or changed to incorporate features of nearby sounds (Lahey & Ernestus, 2014; Warner, 2019). Indeed, many instances of words in spontaneous speech are so different, or phonetically reduced, compared to the canonical form that they are phonetically uninterpretable in isolation (Bard & Anderson, 1983). This raises important questions about what young children, who are still learning the language they are trying to comprehend, understand about reduced pronunciation variants. In this study, we will test how well young children recognize reduced forms of common words and how the preceding context (presence or absence of a clear instance of the same word) influences recognition.

  Publisher

• The intelligibility of consonants in American English infant-directed speech

  Cognitive Psychology · 2025-10-13

  articleOpen access1st authorCorresponding

  To begin learning their language, infants must locate words in the speech signal. Some models of word discovery presuppose that the discovery process depends on identifying phonetic segments (phones) in speech. To test the plausibility of models arguing that infants can reliably categorize consonants in speech, adult native speakers were asked to identify the consonant in vowel-consonant-vowel sequences extracted from spontaneous English infant-directed speech. Listeners could consistently identify some instances of consonants (for example, correctly indicating that an /s/ was an /s/). But many tokens (about half) were not consistently identifiable. Performance was significantly worse for codas than onsets. Providing the full utterance context in low-pass-filtered form did not aid recognition, nor did familiarization with the talker. In a second task, listeners were barely above chance in guessing whether a consonant was a word onset or a word-final coda. Performance on infant-directed speech was not markedly better than performance on a comparison set of adult-directed speech consonants. Erroneous responses frequently had little systematic resemblance to the correct answer. The results suggest that it is not plausible that infants can parse most utterances exhaustively into strings of uttered speech sounds and feed those strings into a statistical clustering mechanism.

  PublisherDOI

• Intelligibility to Adults of Consonants in VCVs, with Speech from Brent and Buckeye Corpora: Stimuli and Datasets

  OSF Preprints (OSF Preprints) · 2025-01-01

  datasetOpen access1st authorCorresponding

  Stimuli and data for Swingley, D. (2025), The intelligibility of consonants in American English infant-directed speech, Cognitive Psychology. doi.org/10.1016/j.cogpsych.2025.101766

  PublisherOA PDFDOI

• Development in the comprehension of phonetically reduced spoken words.

  PubMed · 2025-01-01

  articleOpen accessSenior author

  The speech young children hear is highly variable. For example, reduced pronunciations, where some sounds in the canonical pronunciation are naturally dropped or altered, are common even in speech to children. The present study employed a new story-guided looking method (a variation on language-guided looking) to create felicitous conditions for testing young children's recognition of reduced pronunciations of familiar words. Experiment 1 (18-24 months, n=32) found that toddlers succeeded at recognizing clear pronunciations, but failed to recognize reduced pronunciations, even in repetition trials when target words were preceded by a clear mention of the same word in the previous sentence. In Experiment 2, 3-year-olds (35-39 months, n=17 out of 44 pre-registered, ongoing) succeeded at recognizing reduced pronunciations, and benefited from preceding repetition. Overall, these results demonstrate a powerful new method for studying children's language comprehension under more naturalistic conditions, and highlight an important psycholinguistic development over the 2-3 year span.

  PublisherOA PDF

• The clarity of word repetitions in American English infant-directed speech

  Journal of Child Language · 2025-09-15

  articleOpen access1st authorCorresponding

  Words in infant-directed speech (IDS) are often phonetically reduced. This likely renders words harder for infants to learn and recognize. This difficulty might be mitigated by the repetitive nature of IDS, in particular if reduced instances are often preceded by clear instances (i.e., the first-mention effect). To characterize phonetic clarity in American English word repetitions, words were extracted from the IDS of eight mothers and presented to adults (n = 36) who judged their clarity. First mentions of repeated words were found to be clearer than second mentions, though this effect was small. Clarity was rated as greater for less common words and for utterance-final words. Clarity was also greater for words parents thought their child knew. The results help guide intuitions about the phonetic problem infants face when learning their first words.

  PublisherOA PDFDOI

• Development in the comprehension of phonetically reduced spoken words

  Underline Science Inc. · 2025-06-18

  otherOpen accessSenior author

  The speech young children hear is highly variable. For example, reduced pronunciations, where some sounds in the canonical pronunciation are naturally dropped or altered, are common even in speech to children. The present study employed a new story-guided looking method (a variation on language-guided looking) to create felicitous conditions for testing young children’s recognition of reduced pronunciations of familiar words. Experiment 1 (18-24 months, n=32) found that toddlers succeeded at recognizing clear pronunciations, but failed to recognize reduced pronunciations, even in repetition trials when target words were preceded by a clear mention of the same word in the previous sentence. In Experiment 2, 3-year-olds (35-39 months, n=17 out of 44 pre-registered, ongoing) succeeded at recognizing reduced pronunciations, and benefited from preceding repetition. Overall, these results demonstrate a powerful new method for studying children’s language comprehension under more naturalistic conditions, and highlight an important psycholinguistic development over the 2–3 year span.

  PublisherDOI

• Developmental change in English‐learning children's interpretations of salient pitch contours in word learning

  Infancy · 2024-02-29 · 2 citations

  articleOpen accessSenior author

  To efficiently recognize words, children learning an intonational language like English should avoid interpreting pitch-contour variation as signaling lexical contrast, despite the relevance of pitch at other levels of structure. Thus far, the developmental time-course with which English-learning children rule out pitch as a contrastive feature has been incompletely characterized. Prior studies have tested diverse lexical contrasts and have not tested beyond 30 months. To specify the developmental trajectory over a broader age range, we extended a prior study (Quam & Swingley, 2010), in which 30-month-olds and adults disregarded pitch changes, but attended to vowel changes, in newly learned words. Using the same phonological contrasts, we tested 3- to 5-year-olds, 24-month-olds, and 18-month-olds. The older two groups were tested using the language-guided-looking method. The oldest group attended to vowels but not pitch. Surprisingly, 24-month-olds ignored not just pitch but sometimes vowels as well-conflicting with prior findings of phonological constraint at 24 months. The youngest group was tested using the Switch habituation method, half with additional phonetic variability in training. Eighteen-month-olds learned both pitch-contrasted and vowel-contrasted words, whether or not additional variability was present. Thus, native-language phonological constraint was not evidenced prior to 30 months (Quam & Swingley, 2010). We contextualize our findings within other recent work in this area.

  PublisherOA PDFDOI

• Computational Modeling of the Segmentation of Sentence Stimuli From an Infant Word‐Finding Study

  Cognitive Science · 2024-03-01 · 2 citations

  articleOpen access1st authorCorresponding

  Computational models of infant word-finding typically operate over transcriptions of infant-directed speech corpora. It is now possible to test models of word segmentation on speech materials, rather than transcriptions of speech. We propose that such modeling efforts be conducted over the speech of the experimental stimuli used in studies measuring infants' capacity for learning from spoken sentences. Correspondence with infant outcomes in such experiments is an appropriate benchmark for models of infants. We demonstrate such an analysis by applying the DP-Parser model of Algayres and colleagues to auditory stimuli used in infant psycholinguistic experiments by Pelucchi and colleagues. The DP-Parser model takes speech as input, and creates multiple overlapping embeddings from each utterance. Prospective words are identified as clusters of similar embedded segments. This allows segmentation of each utterance into possible words, using a dynamic programming method that maximizes the frequency of constituent segments. We show that DP-Parse mimics American English learners' performance in extracting words from Italian sentences, favoring the segmentation of words with high syllabic transitional probability. This kind of computational analysis over actual stimuli from infant experiments may be helpful in tuning future models to match human performance.

  PublisherOA PDFDOI

• Data From: Developmental Change in English-Learning Children’s Interpretations of Salient Pitch Contours in Word Learning

  2024-01-18

  datasetOpen accessSenior author

  To efficiently recognize words, children learning an intonational language like English should avoid interpreting pitch-contour variation as signaling lexical contrast, despite the relevance of pitch at other levels of structure. Thus far, the developmental time-course with which English-learning children rule out pitch as a contrastive feature has been incompletely characterized. Prior studies have tested diverse lexical contrasts and have not tested beyond 30 months. To specify the developmental trajectory over a broader age range, we extended a prior study (Quam & Swingley, 2010), in which 30-month-olds and adults disregarded pitch changes, but attended to vowel changes, in newly learned words. Using the same phonological contrasts, we tested 3- to 5-year-olds, 24-month-olds, and 18-month-olds. The older two groups were tested using the language-guided-looking method. The oldest group attended to vowels but not pitch. Surprisingly, 24-month-olds ignored not just pitch but sometimes vowels as well—conflicting with prior findings of phonological constraint at 24 months. The youngest group was tested using the Switch habituation method, half with additional phonetic variability in training. Eighteen-month-olds learned both pitch-contrasted and vowel-contrasted words, whether or not additional variability was present. Thus, native-language phonological constraint was not evidenced prior to 30 months (Quam & Swingley, 2010). Given the surprising insensitivity to mispronunciations at 24 months, we tested 24-month-olds in two additional experiments, which are reported in Supplemental Materials. Experiment S1 tested 24-month-olds in the low-variability condition of the Switch procedure used at 18 months, finding that—in contrast to 18-month-olds—24-month-olds did not detect switches to the trained word-object pairings when the switches involved either a pitch change or a vowel change. Experiment S2 again used Switch habituation training, but tested children in a language-guided looking test instead of a Switch test (Yoshida, Fennell, Swingley, & Werker, 2009). Again, 24-month-olds showed no evidence of detecting subtle differences in word pronunciations. The data from all five experiments (1, 2, 3, S1, S2) are included in the data files in the interests of transparency.

  PublisherOA PDFDOI

• How Infants Link Nonce Phrases to Scenes With Objects and Predicates

  Developmental Science · 2024-10-21

  articleSenior author

  When infants hear sentences containing unfamiliar words, are some language-world links (such as noun-object) more readily formed than others (verb-predicate)? We examined English learning 14-15-month-olds' capacity for linking referents in scenes with bisyllabic nonce utterances. Each of the two syllables referred either to the object's identity, or the object's motion. Infants heard the syllables in either a Verb-Subject (VS) or Subject-Verb (SV) order. Learning was tested using preferential looking. The results showed that infants learned the nouns and verbs equally well. In addition, in both the VS- and SV-consistent conditions, infants learned the meaning of the utterance-final syllable, but not the utterance-initial one. A follow-up experiment that manipulated the prosodic cues of the test phrases confirmed that infants had decomposed the bisyllabic phrases into two distinct word-units. Thus, any biases potentially favoring noun or verb learning played a smaller role than utterance position did when noun and verb learning were equally supported by context.

  PublisherDOI

Recent grants

• Learning words and speech sounds in infancy

  NSF · $711k · 2019–2024

• NIH Grant F32HD008307

  NIH · $50k

• Contributions of infant learning to language acquisition

  NIH · $3.0M · 2006–2019

Frequent coauthors

• Carolyn Quam

  Portland State University

  10 shared

• Martijn Goudbeek

  Tilburg University

  8 shared

• Anne Fernald

  Stanford University

  8 shared

• Isabelle Dautriche

  Laboratoire de Psychologie Cognitive

  7 shared

• Anne Cutler

  Western Sydney University

  7 shared

• Anne Christophe

  École des hautes études en sciences sociales

  7 shared

• Elika Bergelson

  Harvard University

  6 shared

• Roel Smits

  Philips (Netherlands)

  6 shared

Labs

• Swingley LabPI

Education

• PhD, Psychology

  Stanford University

  1997

• toward BA, Psychology

  Queen's College, University of Oxford

  1991