About

Andrea Megela Simmons received her A.B. degree from the University of Pennsylvania and her Ph.D. degree from Harvard University. She conducted postdoctoral research at Cornell University. She is currently a Professor of Cognitive, Linguistic, & Psychological Sciences at Brown University, with a secondary appointment in the Department of Neuroscience. She is a member of the Carney Institute for Brain Science. Her research interests encompass cognitive and neural mechanisms of sound perception and communication in a variety of animals, including frogs, echolocating bats, dolphins, and humans. She is currently a principal investigator on an ONR MURI project.

Research topics

• Computer Science
• Speech recognition
• Physics
• Acoustics
• Telecommunications
• Optics
• Biology

Selected publications

• Simulated target search by bats using biomimetic SCAT biosonar model

  Frontiers in Computational Neuroscience · 2026-04-08

  articleOpen accessSenior author

  Echolocating big brown bats broadcast short, wideband ultrasonic FM pulses for foraging and navigation. These broadcasts contain frequencies from 100 to 20 kHz (wavelengths 0.34-1.7 cm). Bats perceive target distance by measuring the time delay between the outgoing pulse and the returning echo. Acuity of this delay perception depends on the frequency content of echoes and the associated microsecond-level coherence between neural representations of the 1st and 2nd harmonic frequencies. Bats perceive target shape by estimating differences in the delay of mini-echoes from different reflecting points, or glints, within the target. A matched-filter receiver would register glints as prominent peaks in the pulse-echo cross-correlation output, but in bats the overlapping glint reflections mix together to create echo interference patterns that are transposed back into delay estimates. The process is modeled as spectrogram correlation and transformation (SCAT). The first, nearest glint is registered by echo delay itself, but subsequent glints are extracted from the nulls in the interference spectrum. Here, the SCAT receiver was evaluated for its ability to locate targets with a specific glint spacing in the 2D range/cross-range plane while rejecting other targets with larger or smaller spacings.

  PublisherOA PDFDOI

• Biosonar dynamics and spatial attention in an unpredictable virtual localization task

  Journal of Experimental Biology · 2026-01-13

  articleOpen accessSenior author

  Echolocating big brown bats hunt insects flying along unpredictable paths in front of vegetation. We conducted three psychophysical experiments to investigate how these bats alter their spatial attention when localizing virtual target echoes appearing unpredictably in azimuth and against weak physical clutter. Four bats were trained to detect virtual echoes presented from a 120 deg azimuthal array of six loudspeakers. Within a single trial, echoes could remain in the same position or shift unpredictably to a new one. The bats performed well in stationary trials but were less accurate when targets shifted more peripherally and contralaterally to the original azimuth. They aimed their sonar beams accurately at targets appearing centrally; they were less precise but faster when localizing targets in the periphery, maintaining a more central acoustic gaze with only momentary peripheral shifts. When localizing a shifted target, bats reduced the interpulse intervals between broadcasts and emitted proportionally more sonar sound groups, suggesting increased perceived task difficulty. Weak clutter located closely behind the virtual target reduced accuracy in localizing target shifts, affected the speed of beam aim adjustment, and was associated with an increase in broadcast duration. Interpulse intervals and sonar sound groups were not strongly affected by clutter. Behavioral differences between bats showed the impact of individual problem-solving strategies. These findings demonstrate that the distribution of spatial attention is biased towards the center of the ensonified field of view and is influenced by weak background clutter.

  PublisherOA PDFDOI

• The Editors’ and Readers’ Choice Awards 2026: sustained recognition of outstanding articles in the Journal of Comparative Physiology A

  Journal of Comparative Physiology A · 2026-02-23

  articleOpen access
  PublisherOA PDFDOI

• Auditory brainstem response parameters in big brown bats are insensitive to echo glint structure

  JASA Express Letters · 2025-08-01

  articleOpen access1st authorCorresponding

  Echolocating big brown bats (Eptesicus fuscus) perceive a target's reflecting parts, or glints, from spectral peaks and nulls in echoes. Glints serve as cues for object size and shape. In this exploratory study, we investigated whether the scalp-recorded auditory brainstem response (ABR) carries information about glints. We show that ABR amplitude, latency, and root mean square energy do not differentiate between glints in a manner paralleling the bat's perception. ABR recordings, even though they encode some perceptually relevant features of echoes, may not be sensitive enough to distinguish these more subtle cues.

  PublisherDOI

• Cochlear representation of wideband biosonar sounds and the emergence of neural oscillations

  Hearing Research · 2025-04-07

  reviewOpen accessSenior author

  Echolocating big brown bats and bottlenose dolphins broadcast wideband ultrasonic echolocation calls in the baseband to sense their surroundings. Even though these species inhabit different media and emit echolocation calls with different spectra, both show similar perceptual acuity: They determine target range from echo delay, they detect changes in echo delay on a microsecond scale, and they perceive ultrasonic phase. These perceptual performances are too acute to understand on the basis of single neuron responses, and even neural population responses do not reach the required behavioral values. Here we propose two mechanisms that may contribute to temporal hyperacuity in these wideband echolocators. Structural imaging studies show that in both species the cochlea receives input from the middle ear at locations different from that seen in non-echolocating mammals. These unusual patterns of input might produce interference patterns in traveling waves along the basilar membrane, which in turn could facilitate detection of ultrasonic phase by producing low difference frequencies that may form a substrate for further neural processing into perception. The second mechanism is related to oscillations of evoked activity observed in the bat's inferior colliculus, which could create broadcast-echo interference patterns at the neural level. The resulting difference-frequency interference signals would be very sensitive to changes in echo delay and phase. Small changes in ultrasonic sounds thus could lead to much larger changes in neural response timing by magnifying echo time itself.

  PublisherDOI

• From mechanoecology to sensory physiology to olfactory navigation: the Editors’ and Readers’ Choice Awards 2025

  Journal of Comparative Physiology A · 2025-03-01

  editorialOpen accessSenior author
  PublisherOA PDFDOI

• Amphibians

  2025-01-01

  book-chapterOpen access1st authorCorresponding

  Abstract This chapter describes sound production, sound sensing, and sound usage in amphibians, focusing on the Anura (the anurans or tailless amphibians, i.e., frogs and toads). Anurans are the most vocal amphibians, and considerably more information is available on their hearing abilities than on those of the other amphibian orders, the Caudata (the urodeles or tailed amphibians, i.e., salamanders and newts) and the Gymnophiona (the caecilians or limbless amphibians). Within anurans, bioacoustic research has focused on the production and perception of the male’s species-specific advertisement call, an essential vocalization for reproductive isolation and mate choice. This chapter describes acoustic features of advertisement calls, how they are produced in the vocal tract, how they are processed in the ear, how hearing abilities are reflected in auditory brainstem responses, and how anthropogenic noise impacts communication. The unique structure of the anuran ear is described in the context of its considerable diversity depending on habitat and developmental stage.

  PublisherOA PDFDOI

• Echolocation calls of some bat species in western Uganda

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-12-15

  articleOpen accessSenior author

  ABSTRACT With the rise of accessible recording technology, passive acoustic monitoring can be an affordable and rapid way to assess species richness, even when individual animals cannot be captured due to regulatory or practical obstacles. Motivated by the relative lack of data and in partnership with the local populace, we recorded echolocation calls of freely-flying bats across six locations in rural western Uganda using opportunistic passive acoustic recordings. Frequency-modulated echolocation calls were recorded at all six locations, while constant-frequency calls were recorded only at sites near entrances to caves. Preliminary species identifications were made using Kaleidoscope Pro, habitat distribution maps for Uganda, and by reference to published work. We make our acoustic recordings publicly available to serve as a resource for further explorations of the richness of bat species in Uganda.

  PublisherDOI

• Social calls of big brown bats in a competitive feeding context

  Frontiers in Ecology and Evolution · 2025-11-20

  articleOpen accessSenior authorCorresponding

  Big brown bats ( Eptesicus fuscus ) have a diverse vocal repertoire. We tested the hypothesis that frequency-modulated bouts (FMBs) are male-specific calls produced during food competition. Seven pairs of bats (male-male, male-female, female-female) competed in the laboratory to capture a food item. Within this restricted behavioral context, we identified six common social call types, broadly classified as aggressive in previous literature. Female-female pairs produced significantly fewer calls than the pairs containing males, and their social calls were longer in duration. FMB calls were absent in all female-female pairs but were present, in varying numbers, in pairs containing males. FMBs recorded in the laboratory resembled those recorded from big brown bats foraging in the wild. Results support the hypothesis that FMBs are produced in foraging interactions in both the laboratory and the field, and confirm previous reports of less robust vocal interactions between female bats.

  PublisherOA PDFDOI

• One hundred years of excellence: the top one hundred authors of the Journal of Comparative Physiology A

  Journal of Comparative Physiology A · 2024-03-01 · 8 citations

  articleOpen accessSenior author

  The Journal of Comparative Physiology A is the premier peer-reviewed scientific journal in comparative physiology, in particular sensory physiology, neurophysiology, and neuroethology. Founded in 1924 by Karl von Frisch and Alfred Kühn, it celebrates its 100th anniversary in 2024. During these 100 years, many of the landmark achievements in these disciplines were published in this journal. To commemorate these accomplishments, we have compiled a list of the Top 100 Authors over these 100 years, representing approximately 1% of all its authors. To select these individuals, three performance criteria were applied: number of publications, total number of citations attracted by these articles, and mean citation rate of the papers published by each author. The resulting list of the Top 100 Authors provides a fascinating insight into the history of the disciplines covered by the Journal of Comparative Physiology A and into the academic careers of many of their leading representatives.

  PublisherOA PDFDOI

Recent grants

• NIH Grant R01DC005257

  NIH · $1.6M · 2008

• NIH Grant R01NS021911

  NIH · $134k · 1988

• NIH Grant R01NS028565

  NIH · $1.6M · 2002

Frequent coauthors

• James A. Simmons

  Providence College

  256 shared

• Seth S. Horowitz

  51 shared

• Amaro Tuninetti

  Providence College

  45 shared

• Kelsey N. Hom

  39 shared

• Hiroshi Riquimaroux

  35 shared

• Chen Ming

  Sichuan University

  33 shared

• Michael J. Ferragamo

  26 shared

• Michaela Warnecke

  Brown University

  25 shared

Awards & honors

• The Lewis Paeff and Edna Duchin Lipsitt Lecture in Child Dev…