Mats NilssonProfessor
About me
I am researching how we experience and are affected by sound and noise. My previous research primarily focused on the health effects of traffic noise and experiences of sound environments in green areas. In recent years, my research has focused on basic auditory abilities, especially concerning blind individuals' ability to use sound information for navigating their surroundings (known as 'echolocation').
Since 2021, I have been the study director for the doctoral program in psychology at the Department of Psychology.
Swedish Acoustic Society's Sound Prize 2022
On March 22, 2023, I received the Swedish Acoustic Society's Sound Prize 2022. It was awarded at their annual Sound Day. In addition to honor and a diploma, I also received a miniature of one of Carl Milles' Musicians' Angels.
Citation
"The Swedish Acoustic Society's Sound Prize 2022 is awarded to Professor Mats Nilsson at Stockholm University for outstanding contributions in psychoacoustics and epidemiology with a focus on noise across various scientific areas and applications. Mats Nilsson has contributed to the development of Gösta Ekman's Laboratory for psychophysical research at Stockholm University and has researched soundscapes, masking of both traffic noise and wind turbine noise, cognition of various noise sources, including how these change with noise-reducing measures such as noise barriers. In recent years, he has also worked on sound perception for the blind and how individuals with visual impairments use echolocation through click sounds."
Read more at www.akustiska-sallskapet.org
Research
My research interests
- Psychoacoustics
- Auditory learning and expertise
- Effects of environmental sounds on health and well-being
- Research methods for the behavioral sciences
Publications on Google Scholar
Research projects
Publications
A selection from Stockholm University publication database
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Comparing Echo-Detection and Echo-Localization in Sighted Individuals
2021. Carlos Tirado (et al.). Perception 50 (4), 308-327
ArticleRead more about Comparing Echo-Detection and Echo-Localization in Sighted IndividualsEcholocation is the ability to gather information from sound reflections. Most previous studies have focused on the ability to detect sound reflections, others on the ability to localize sound reflections, but no previous study has compared the two abilities in the same individuals. Our study compared echo-detection (reflecting object present or not?) and echo-localization (reflecting object to the left or right?) in 10 inexperienced sighted participants across 10 distances (1-4.25 m) to the reflecting object, using an automated system for studying human echolocation. There were substantial individual differences, particularly in the performance on the echo-localization task. However, most participants performed better on the detection than the localization task, in particular at the closest distances (1 and 1.7 m), illustrating that it sometimes may be hard to perceive whether an audible reflection came from the left or right.
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Individual differences in the ability to access spatial information in lag-clicks
2021. Carlos Tirado, Billy Gerdfeldter, Mats E. Nilsson. Journal of the Acoustical Society of America 149 (5), 2963-2975
ArticleRead more about Individual differences in the ability to access spatial information in lag-clicksIt may be difficult to determine whether a dichotic lag-click points to the left or right when preceded by a diotic lead-click. Previous research suggests that this loss of spatial information is most prominent at inter-click intervals (ICIs) <10 ms. However, a study by Nilsson, Tirado, and Szychowska [(2019). J. Acoust. Soc. Am. 145, 512–524] found support for loss of spatial information in lag-clicks at much longer ICIs using a stimulus setup differing from those in previous research. The present study used a setup similar to that of the Nilsson, Tirado, and Szychowska study [(2019). J. Acoust. Soc. Am. 145, 512–524] to measure 13 listeners' ability to lateralize (left versus right) and detect (present versus absent) the lag-click in lead–lag click pairs with ICIs of 6–48 ms. The main finding was distinct individual differences in performance. Some listeners could lateralize lag-clicks all the way down to their detection threshold, whereas others had lateralization thresholds substantially higher than their detection thresholds, i.e., they could not lateralize lag-clicks that they could easily detect. Two such listeners trained for 30 days and managed to improve their lateralization thresholds to reach their detection thresholds, but only at longer ICIs (>20 ms), suggesting different mechanisms underlying lag-click lateralization at short versus long ICIs.
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The reminiscence bump is blind to blindness
2020. Stina Cornell Kärnekull (et al.). Consciousness and Cognition 78
ArticleRead more about The reminiscence bump is blind to blindnessThe reminiscence bump is the disproportionally high reporting of autobiographical memories from adolescence and early adulthood and is typically observed when memories are evoked by cues, such as words, pictures, and sounds. However, when odors are used the bump shifts to early childhood. Although these findings indicate that sensory modality affects the bump, the influence of the individual's sensory function on the reminiscence bumps is unknown. We examined the reminiscence bumps of sound- and odor-evoked autobiographical memories of early blind and sighted individuals, since early blindness implies considerable effects on sensory experience. Despite differences in sensory experience between blind and sighted individuals, the groups displayed similar age distributions of both sound- and odor-evoked memories. The auditory bump spanned the first two decades of life, whereas the olfactory bump was once again found in early childhood. These results demonstrate that the reminiscence bumps are robust to fundamental differences in sensory experience.
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Disruption of writing by background speech
2019. Marijke Keus van de Poll, Louise Sjödin, Mats E. Nilsson. Applied Cognitive Psychology 33 (4), 537-543
ArticleRead more about Disruption of writing by background speechIt is not unusual that people have to write in an environment where background speech is present. Background speech can vary in both speech intelligibility and location of the sound source. Earlier research has shown disruptive effects of background speech on writing performance. To expand and reinforce this knowledge, the present study investigated the role of number of voices and sound source location in the relation between background speech and writing performance. Participants wrote texts in quiet or in background speech consisting of one or seven voices talking simultaneously located in front of or behind them. Overall, one voice was more disruptive than seven voices talking simultaneously. Self-reports showed that sound from the front was more disruptive compared with sound from behind. Results are in line with theory of interference-by-process, attentional capture, and the cross-modal theory of attention. The relevance of the results for open-office environments is discussed.
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Four-decision tests for stochastic dominance, with an application to environmental psychophysics
2019. Angel G. Angelov (et al.). Journal of mathematical psychology (Print) 93
ArticleRead more about Four-decision tests for stochastic dominance, with an application to environmental psychophysicsIf the survival function of a random variable X lies to the right of the survival function of a random variable Y, then X is said to stochastically dominate Y. Inferring stochastic dominance is particularly complicated because comparing survival functions raises four possible hypotheses: identical survival functions, dominance of X over Y, dominance of Y over X, or crossing survival functions. In this paper, we suggest four-decision tests for stochastic dominance suitable for paired samples. The tests are permutation-based and do not rely on distributional assumptions. One-sided Cramer-von Mises and Kolmogorov-Smirnov statistics are employed but the general idea may be utilized with other test statistics. The power to detect dominance and the different types of wrong decisions are investigated in an extensive simulation study. The proposed tests are applied to data from an experiment concerning the individual's willingness to pay for a given environmental improvement.
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Psychoacoustic evidence for stronger discrimination suppression of spatial information conveyed by lag-click interaural time than interaural level differences
2019. Mats E. Nilsson, Carlos Tirado, Malina Szychowska. Journal of the Acoustical Society of America 145 (1), 512-524
ArticleRead more about Psychoacoustic evidence for stronger discrimination suppression of spatial information conveyed by lag-click interaural time than interaural level differencesListeners have limited access to spatial information in lagging sound, a phenomenon known as discrimination suppression. It is unclear whether discrimination suppression works differently for interaural time differences (ITDs) and interaural level differences (ILDs). To explore this, three listeners assessed the lateralization (left or right) and detection (present or not) of lag clicks with a large fixed ITD (350 mu s) or ILD (10 dB) following a diotic lead click, with inter-click intervals (ICIs) of 0.125-256 ms. Performance was measured on a common scale for both cues: the lag-lead amplitude ratio [dB] at 75% correct answers. The main finding was that the lateralization thresholds, but not detection thresholds, were more strongly elevated for ITD-only than ILD-only clicks at intermediate ICIs (1-8 ms) in which previous research has found the strongest discrimination suppression effects. Altogether, these findings suggest that discrimination suppression involves mechanisms that make spatial information conveyed by lag-click ITDs less accessible to listeners than spatial information conveyed by lag-click ILDs.
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The Echobot
2019. Carlos Tirado, Peter Lundén, Mats E. Nilsson. PLOS ONE 14 (10)
ArticleRead more about The EchobotEcholocation is the detection and localization of objects by listening to the sounds they reflect. Early studies of human echolocation used real objects that the experimental leader positioned manually before each experimental trial. The advantage of this procedure is the use of realistic stimuli; the disadvantage is that manually shifting stimuli between trials is very time consuming making it difficult to use psychophysical methods based on the presentation of hundreds of stimuli. The present study tested a new automated system for stimulus presentation, the Echobot, that overcomes this disadvantage. We tested 15 sighted participants with no prior experience of echolocation on their ability to detect the reflection of a loudspeaker-generated click from a 50 cm circular aluminum disk. The results showed that most participants were able to detect the sound reflections. Performance varied considerably, however, with mean individual thresholds of detection ranging from 1 to 3.2 m distance from the disk. Three participants in the loudspeaker experiment also tested using self-generated vocalization. One participant performed better using vocalization and one much worse than in the loudspeaker experiment, illustrating that performance in echolocation experiments using vocalizations not only measures the ability to detect sound reflections, but also the ability to produce efficient echolocation signals. Overall, the present experiments show that the Echobot may be a useful tool in research on human echolocation.
Show all publications by Mats Nilsson at Stockholm University