Summary: New research from the Weizmann Institute of Science shows that mice use not only touch but also sound produced by their whiskers to perceive the world. Subtle noises generated during whisking are encoded in the auditory cortex and can be interpreted as an independent sensory signal, even when tactile input is blocked.
Behavioral experiments confirmed that mice can identify objects using only the sounds their whiskers make, demonstrating multisensory integration between touch and hearing. These findings expand our understanding of active sensing and suggest possible applications in robotics, prosthetics, and sensory rehabilitation.
Key facts:
- Multisensory integration: Whisker-generated sounds are processed by the auditory cortex independently of tactile pathways.
- Behavioral evidence: Mice can identify objects based solely on whisker-generated sounds when touch is disabled.
- Applied potential: Insights may inform prosthetic design, sensory rehabilitation, and robotic sensing systems.
Source: Weizmann Institute of Science
Living in dim or cluttered environments, mice rely heavily on their whiskers—an active sensing behavior called whisking—to explore nearby objects. Traditionally, whisking has been treated as a purely tactile process. The new study led by Prof. Ilan Lampl at the Weizmann Institute reframes whisking as a multimodal behavior in which touch and sound both contribute to perception.
Published in Current Biology, the study shows that whisking produces faint acoustic signatures well within the hearing range of mice. The research team recorded these ultrasound-rich sounds using sensitive microphones positioned roughly the same distance from the whiskers as a mouse’s ear. They then compared those acoustic recordings with neural activity measured in the auditory cortex while mice actively brushed their whiskers against different surfaces.
Auditory cortex responses tracked the presence and identity of objects contacted by whiskers, even after the researchers selectively blocked somatosensory input from the whiskers. This dissociation demonstrates that the auditory system responds directly to the sounds of whisking rather than receiving only secondary signals from touch pathways.
To test whether these auditory signals are behaviorally meaningful, the team used machine learning and behavioral training. First, an algorithm was trained to classify objects using patterns of neural activity recorded in the auditory cortex; it reliably discriminated object identity. A second model was trained on the recorded whisker sounds and achieved similar performance, supporting the conclusion that auditory cortex activity reflects acoustic information from whisking.
Finally, in a behavioral test, mice with abolished whisker touch sensation were trained to recognize objects such as aluminum foil using only whisker-generated sounds. The mice consistently responded to these sounds, demonstrating they can associate the acoustic cues with object identity in a natural, active sensing context.
Prof. Lampl summarizes that the vibrissa system—the neural circuits governing whisker movements—operates in an integrative, multimodal way during exploration. From an evolutionary perspective, combining tactile and auditory cues likely offers adaptive advantages: mice could assess environmental features quietly and with low risk of detection, determine whether vegetation is hollow or juicy, or choose safer paths through fields where silence matters.
Beyond fundamental neuroscience, these findings suggest new research and engineering directions. If the brain can decode and combine faint acoustic and tactile signals from the same motor act, similar principles might enhance prosthetic feedback, rehabilitation protocols after brain injury, or sensory substitution strategies for visually impaired people. Designers of robotic systems could also draw inspiration from whisker-based multisensory integration to build compact, low-energy sensors that detect obstacles by combining tactile motions with acoustic feedback—useful in low-visibility conditions such as smoke or fog.
Science numbers
Mouse whiskers are roughly 40–80 microns in diameter at the base—comparable to an average human hair—and taper to tips of about 3–4 microns.
These anatomical details, together with the finding that whisking generates audible cues, highlight how small biomechanical movements can create usable sensory signals. Existing training methods for the blind, such as using white-cane sounds to infer surface properties, already exploit similar cross-modal cues; the new results suggest further refinements and new applications.
Dr. Ben Efron, with colleagues Athanasios Ntelezos and Yonatan Katz, helped lead the experiments that combined acoustic recording, in vivo neural measurements, machine-learning decoding, and behavioral tests. Their multidisciplinary approach clarifies how the auditory cortex encodes whisker sounds and how that encoding supports perception.
About this neuroscience research news
Author: Maayan Shain
Source: Weizmann Institute of Science
Contact: Maayan Shain – Weizmann Institute of Science
Image: The image is credited to Neuroscience News
Original research: Detection and neural encoding of whisker-generated sounds in mice — Ilan Lampl et al., Current Biology (open access).
Abstract
Detection and neural encoding of whisker-generated sounds in mice
The vibrissa system enables active sensing through whisker movements and has traditionally been viewed as a tactile system. This study asks whether whisking against objects produces sounds that mice can detect and whether auditory circuits represent that information.
Recordings show that head-fixed mice whisking against objects generate audible sounds within the mice’s hearing range. When tactile sensation from the vibrissae was abolished, neuronal firing in auditory cortex remained strongly modulated by whisking against objects. Object identity could be decoded reliably from auditory cortical activity, closely matching decoding based on simultaneous sound recordings, indicating that neural responses reflect acoustic features of whisking. Finally, trained mice lacking vibrissa touch sensation correctly identified objects using only whisker-generated sounds.
These results indicate that, in rodents, the vibrissa system engages both tactile and auditory modalities during active exploration, revealing a multimodal mechanism for environmental perception.