Jonathan Peelle, PhD, Associate Professor, Otolaryngology—Head & Neck Surgery
Although our ears are necessary for us to process sounds, it is in our brains that we make sense of this information. When speech is unclear—for example, due to background noise or hearing impairment—our brains must work harder to understand what has been said. This extra challenge requires more cognitive effort, and can detract from other types of tasks that we want to do. That is, when we listen to a speaker in a noisy restaurant, we may find it more difficult remembering what has been said, because we had to spend so much effort understanding the words in the first place.
Research in our lab is focused primarily on understanding how the brain understands speech, and how this is affected by changes in cognitive and hearing ability. We study speech and auditory processing in adults of all ages and varying levels of hearing. We use a combination of behavioral testing and brain imaging to investigate the cognitive processes involved in speech comprehension and how cognitive demands vary between listeners. Some of the brain imaging techniques we rely on are structural magnetic resonance imaging (MRI), functional MRI, and high-density diffuse optical tomography (HD-DOT).
Listening effort and the neural consequences of acoustic challenge
We frequently listen to speech that is acoustically degraded due to background noise, foreign accents, or as a result of hearing loss. In these situations, a listener’s brain must make sense of an acoustic signal that is less detailed, and thus less certain. How do our brains cope with this type of degraded sensory input? In the case of hearing loss, what are the long-term consequences to neural reorganization and plasticity?
One way we have studied hearing loss is to look at the structure and function of auditory brain regions in listeners over the age of 60, who frequently have some hearing loss. We find that individual differences in hearing ability are correlated with both the pattern of brain activity during speech comprehension, and with the volume of gray matter in auditory cortex. This suggests that hearing impairment is associated with both functional and structural brain changes, which may influence other aspects of language processing.
Age-related changes in speech comprehension
The structural and functional brain networks supporting speech comprehension undergo significant change over our lifetimes. To date our work in this area has focused primarily on adult age-related changes in speech comprehension. Normal aging is an interesting case because it entails changes to both sensory ability (e.g., some degree of hearing loss is typical) and cognitive systems.
What we find is that when listening to spoken sentences, older adults rely on many of the same brain regions as young adults. However, older adults also tend to use some additional regions not used by young adults, especially in frontal cortex. One of the goals of our ongoing work is to better specify the additional cognitive processes involved, and to determine whether these are supporting acoustic processing, linguistic processing, or some combination of the two.
Rhythm and predictability in auditory processing
When we listen to someone talk, one of the many cues we use to predict the upcoming speech signal is the amplitude modulation of the ongoing speech—that is, rhythmic information caused by the opening and closing of the mouth in combination with the vibration of the vocal chords. It has recently been demonstrated that ongoing oscillations in the brain track rhythmic information in speech. We study the way in which this neural “tuning” to predictable temporal information, like that in speech rhythm, helps listeners to process auditory input efficiently.
- Jonathan Peelle, PhD
- Mike Jones, PhD
- Austin Luor
- Sarah McConkey
- Maggie Zink
- Aahana Bajracharya
Financial support for the research done by Dr. Peelle and his collaborators comes from numerous public and private sources, including the Dana Foundation and the National Institutes of Health.
- Koeritzer MA, Rogers CS, Van Engen KJ, Peelle JE (2018) The impact of age, background noise, semantic ambiguity, and hearing loss on recognition memory for speech. Journal of Speech, Language, and Hearing Research 61:740-751. doi:10.1044/2017_JSLHR-H-17-0077
- Peelle JE (2018) Listening effort: How the cognitive consequences of acoustic challenge are reflected in brain and behavior. Ear and Hearing 39:204-214. doi:10.1097/AUD.0000000000000494 (PDF)
- Hassanpour MS, Eggebrecht AT, Peelle JE, Culver JP (2017) Mapping effective connectivity within cortical networks with diffuse optical tomography. Neurophotonics 4:041402. doi:10.1117/1NPh.4.4.041402 (PDF)
- Peelle JE (2017) Optical neuroimaging of spoken language. Language, Cognition and Neuroscience 32:847–854. doi:10.1080/23273798.2017.1290810 (PDF)
- Peelle JE, Wingfield A (2016) Listening effort in age-related hearing loss. The Hearing Journal 69:10, 12. doi:10.1097/01.HJ.0000508368.12042.08
- Peelle JE, Wingfield A (2016) The neural consequences of age-related hearing loss. Trends in Neurosciences 39:486–497. doi:10.1016/j.tins.2016.05.001 (PDF)
- Lee YS, Min NE, Wingfield A, Grossman M, Peelle JE (2016) Acoustic richness modulates the neural networks supporting intelligible speech processing. Hearing Research 333:108–117. doi:10.1016/j.heares.2015.12.008 (PDF)
- Ward CM, Rogers CS, Van Engen KJ, Peelle JE (2016) Effects of age, acoustic challenge, and verbal working memory on recall of narrative speech. Experimental Aging Research 42:126–144. doi:10.1080/0361073X.2016.1108785 (PDF)
- Hassanpour MS, Eggebrecht AT, Culver JP, Peelle JE (2015) Mapping cortical responses to speech using high-density diffuse optical tomography. NeuroImage 117:319–326. doi:10.1016/j.neuroimage.2015.05.058 (PDF)
- Peelle JE, Sommers M (2015) Prediction and constraint in audiovisual speech perception. Cortex 68:169–181. doi:10.1016/j.cortex.2015.03.006 (PDF)
- Peelle JE (2014) Methodological challenges and solutions in auditory functional magnetic resonance imaging. Frontiers in Neuroscience 8:253. doi:10.3389/fnins.2014.00253 (PDF)
- Van Engen KJ, Peelle JE (2014) Listening effort and accented speech. Frontiers in Human Neuroscience 8:577. doi:10.3389/fnhum.2014.00577 (PDF)
- Peelle JE, Gross J, Davis MH (2013) Phase-locked responses to speech in human auditory cortex are enhanced during comprehension. Cerebral Cortex 23:1378–1387. doi:10.1093/cercor/bhs118 (PDF)
- Peelle JE (2012) The hemispheric lateralization of speech processing depends on what “speech” is: A hierarchical perspective. Frontiers in Human Neuroscience 6:309. doi:10.3389/fnhum.2012.00309 (PDF)
- Peelle JE, Davis MH (2012) Neural oscillations carry speech rhythm through to comprehension. Frontiers in Psychology 3:320. doi:10.3389/fpsyg.2012.00320 (PDF)
- Wingfield A, Peelle JE (2012) How does hearing loss affect the brain? Aging Health 8:107–109. doi:10.2217/AHE.12.5 (PDF)
- Peelle JE, Troiani V, Grossman M, Wingfield A (2011) Hearing loss in older adults affects neural systems supporting speech comprehension. Journal of Neuroscience 31:12638–12643. doi:10.1523/jneurosci.2559-11.2011 (PDF)
- Peelle JE, Johnsrude IS, Davis MH (2010) Hierarchical processing for speech in human auditory cortex and beyond. Frontiers in Human Neuroscience 4:51. doi:10.3389/fnhum.2010.00051 (PDF)
- Peelle JE, Troiani V, Wingfield A, Grossman M (2010) Neural processing during older adults’ comprehension of spoken sentences: Age differences in resource allocation and connectivity. Cerebral Cortex 20:773–782. doi:10.1093/cercor/bhp142 (PDF)
660 S. Euclid Ave.
Campus Box 8115
St. Louis, MO 63110
517 S. Euclid Ave.
Rm 810 (office), 811 (lab)
St. Louis, MO 63110