New urban habits in Stockholm following COVID-19.

During the COVID-19 pandemic, physical distancing, mobility restrictions and self-isolation measures were implemented around the world as the primary intervention to prevent the virus from spreading. Urban life has undergone sweeping changes, with people using spaces in new ways. Stockholm is a particularly relevant case of this phenomenon since most facilities, such as day care centres and schools, have remained open, in contrast to cities with a broader lockdown. In this study, we use Twitter data and an online map survey to study how COVID-19 restrictions have impacted the use of different locations, services and amenities in Stockholm. First, we compare the spatial distribution of 87,000 geolocated tweets pre-COVID-19 and during the COVID-19 pandemic. Second, we analyse 895 survey responses asking people to identify places they 'still visit', 'use more', 'avoid' and self-report reasons for using locations. The survey provides a nuanced understanding of whether and how restrictions have affected people. Service and seclusion were found to be important; therefore, the accessibility of such amenities was analysed, demonstrating how changes in urban habits are related to conditions of the local environment. We find how different parts of the city show different capacities to accommodate new habits and mitigate the effects of restrictions on people's use of urban spaces. In addition to the immediate relevance to COVID-19, this paper thus contributes to understanding how restrictions on movement and gathering, in any situation, expose more profound urban challenges related to segregation and social inequality.

Speech level parameters in very low and excessive reverberation measured with a contact-sensor-based device and a headworn microphone.

This work deals with the effect of very low and excessive reverberation on speech sound pressure levels. Measurements were carried out in a semi-anechoic and reverberant room using a contact-sensor-based device fixed at the base of the neck and a headworn microphone placed at 2.5 cm from the speaker's mouth. Speakers produced short monologues and also described a map with the intent of correctly explaining directions to a listener 6 m away. A significant increase of about 2 dB in mean, equivalent, and mode speech levels in semi-anechoic compared to reverberant room was on average observed for the map description from recordings with the contact device, thus, highlighting an increased vocal intensity in dead rooms when the speech task had a communicative intent. Such reliable results were not found with the headworn microphone because speech levels were affected by noise recorded in the pauses. Particularly, the 30 ms logging interval brought to more severe errors in mode and mean speech levels compared to 1 s. When the pauses were removed and a logging interval of 30 ms was adopted, results were more consistent with those obtained with the contact sensor, but level differences between the two rooms still remained not significant.

Intra-speaker and inter-speaker variability in speech sound pressure level across repeated readings.

The intra- and inter-speaker variability of speech sound pressure level (SPL) has been investigated under repeatability conditions in this work. In a semi-anechoic chamber, speech from 17 individuals was recorded with a sound level meter, a headworn microphone, and a vocal monitoring device. The subjects were asked to read twice and in sequence two phonetically balanced passages. The speech variability has been investigated for mean, equivalent, and mode SPL from each reading and device. The intra-speaker variability has been evaluated by means of the average among individual standard deviations in the four readings and it reached the maximum of 2 dB for mode SPL. For the inter-speaker variability, the experimental standard deviation of individual averaged SPL parameters among the four repeated measures has been calculated, obtaining the highest value of 5.3 dB for mode SPL. Changes in SPL variability have been evaluated with different logging intervals for each device. The influence of speech material has been investigated by the Wilcoxon test on paired lists of descriptive statistics for SPL distribution and equivalent SPL in the repeated readings. The data reported in this study may be considered as a preliminary reference for the investigation of changes in speech SPL over subjects.