Stockholms universitet

Mats NilssonProfessor, studierektor

Om mig

Mats mottar Ljudpris 2022

Jag forskar om hur vi upplever och påverkas av ljud och buller. Min tidigare forskning rörde främst hälsoeffekter av trafikbuller och upplevelser av ljudmiljöer i rekreationsområden. På senare år har min forskning rört grundläggande hörselförmågor, särskilt med avseende på blinda personers förmåga att utnyttja ljudinformation för att navigera i omgivningen (så kallad "ekolokalisering"). 

Jag är sedan 2021 studierektor för forskarutbildningen i psykologi vid Psykologiska institutionen.

 

Svenska Akustiska Sällskapets Ljudpris 2022

Den 22 mars 2023 mottag jag Svenska Akustiska Sällskapets Ljudpris 2022. Det delades ut på deras årliga Ljuddag. Förutom ära och diplom fick jag också mottaga en miniatyr av en av Carl Milles Musicerande änglar (se foto). 

Motivering

”Svenska Akustiska Sällskapets Ljudpris 2022 tilldelas professor Mats Nilsson vid Stockholms universitet för framstående insatser inom psykoakustik och epidemiologi med bullerinriktning inom ett flertal vetenskapliga områden och tillämpningar. Mats Nilsson har bidragit till att utveckla Gösta Ekmans Laboratorium för psykofysisk forskning på Stockholms universitet och har bland annat forskat om soundscapes, maskering av både trafikbuller och vindkraftsbuller, kognition av olika bullerkällor bland annat hur dessa förändras av bullerdämpande åtgärder så som till exempel bullerplank. Han har även på senare år arbetat med ljudperception för blinda och hur personer med nedsatt syn använder sig av ekolokalisering genom klick-ljud.”
 
Läs mer på www.akustiska-sallskapet.org

Forskning

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

Click here for my Google scholar page

Forskningsprojekt

Publikationer

I urval från Stockholms universitets publikationsdatabas

  • Comparing Echo-Detection and Echo-Localization in Sighted Individuals

    2021. Carlos Tirado (et al.). Perception 50 (4), 308-327

    Artikel

    Echolocation 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.

    Läs mer om Comparing Echo-Detection and Echo-Localization in Sighted Individuals
  • 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

    Artikel

    It 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.

    Läs mer om Individual differences in the ability to access spatial information in lag-clicks
  • The reminiscence bump is blind to blindness

    2020. Stina Cornell Kärnekull (et al.). Consciousness and Cognition 78

    Artikel

    The 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.

    Läs mer om The reminiscence bump is blind to blindness
  • Disruption of writing by background speech

    2019. Marijke Keus van de Poll, Louise Sjödin, Mats E. Nilsson. Applied Cognitive Psychology 33 (4), 537-543

    Artikel

    It 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.

    Läs mer om Disruption of writing by background speech
  • Four-decision tests for stochastic dominance, with an application to environmental psychophysics

    2019. Angel G. Angelov (et al.). Journal of mathematical psychology (Print) 93

    Artikel

    If 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. 

    Läs mer om Four-decision tests for stochastic dominance, with an application to environmental psychophysics
  • 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

    Artikel

    Listeners 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.

    Läs mer om Psychoacoustic evidence for stronger discrimination suppression of spatial information conveyed by lag-click interaural time than interaural level differences
  • The Echobot

    2019. Carlos Tirado, Peter Lundén, Mats E. Nilsson. PLOS ONE 14 (10)

    Artikel

    Echolocation 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.

    Läs mer om The Echobot

Visa alla publikationer av Mats Nilsson vid Stockholms universitet