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Data from: An improved and highly efficient geometry for facemasks


Cappa, Christopher; Ristenpart, William; Roman, Sanziana (2021), Data from: An improved and highly efficient geometry for facemasks, Dryad, Dataset,


The dataset provided here is associated with the work "An improved and highly efficient geometry for facemasks," by Cappa et al, currently submitted for publication. This includes measurements made of the influence of a new cloth mask, designed originally for singing, on the emission of micron-scale aerosols from various expiratory activities (singing, speaking) and on inhalation of ambient particles. The dataset provided here includes *.txt files exported from an Aerodynamic Particle Sizer that contain time-series of the abundance of particles, by size (in particles per second), measured in the breath of study participants across experiments wherein people were either talking or singing. Also, *.txt files of the measured amplitude of the speech or singing associated with these activities are provided. Data are provided for conditions when people were not wearing any masks or were wearing the new singing masks. For wearing of singing masks, data are provided for participants singing while in various physical orientations with respect to the sampling instrument. Further details, including the file naming scheme, are provided in the associated Read Me file and the Usage Notes. All personally identifying information has been removed.


Participants were asked to perform various expiratory activities (speaking the Rainbow Passage (Talk), singing Ode to Joy (Ode), or singing a song of the participants choice (Song)) while wearing no mask or newly designed singing mask). Study participants performed these activities in front of a funnel connected to an aerodynamic particle sizer (APS, TSI Model 3021), which measured the size-dependent aerosol concentration, and to a condensation particle counter (CPC, TSI Model 3775). Size-dependent concentrations were measured every 1-second during the activities. Additionally, the intensity and duration of the talking and coughing activities were measured using a calibrated microphone. The APS  and CPC inlet was located in a HEPA-filtered laminar flow hood to reduce background counts to near zero. Participants performed activities in different orientations with respect to their position in front of the funnel. These included:

  • No mask: facing straight on, wearing no mask
  • Forward (F): facing straight on, wearing mask
  • Top (T): Head tilted downwards to have bridge of nose in front of funnel, wearing mask
  • Side (S): Head turned sideways to have edge of mask against cheek in front of funnel, wearing mask
  • Bottom (B): Head tilted upwards or above funnel to have chin area in front of funnel, wearing mask

Further details are provided in the associated manuscript (Cappa et al., submitted).

Usage Notes

Please see ReadMe File.

Files Provided:

Provided for each participant/mask type/expiratory activity are the following files:

(i) a text (.txt) file containing the tab-delimited exported files from the APS. Particle sizes are in microns; the smallest size includes all particles measured below that size. Particle counts are given for each size every second. The APS data were exported from the TSI, Inc. AIM software as tab delimited. The file structure for these files is provided below. These files are located in subfolders named by participant ID (e.g., “P1”) and have the naming structure APS_YYYY_M_ZZZZ_PX, where X is the participant number (1-11), YYYY is the designator for each mask type (NoMask or Mask), and ZZZZ is the activity (Talk, Ode, Song), and M is the orientation. 

(ii) a .txt file similar to that from (i) but for the CPC data. The data are tab delimited and exported from the CPC. Particle concentrations are particles cm‑3. File names have the structure CPC_YYYY_M_ZZZZ_PX.

(ii) a .txt file containing the microphone signals (amplitude, in volts) recorded during the activity. The time-interval between points is 2.26757e-5 seconds. These files are provided for both the talking and singing activities. For talking, the total time per file is variable and depends on the amount of time it took for the reading, but is around 100 seconds. For singing the total time is around 140 seconds. There is only one column per file. These files are located in subfolders named by participant ID (e.g., “P1”) and have the naming structure wav_YYYY_M_ZZZZ_FX or wav_YYYY_M_ZZZZ_MX, where X is the participant number (1-11), YYYY is the designator for each mask type (NoMask or Mask), and ZZZZ is the activity (Talk, Ode, Song). 

The above *.txt files are located in subfolders named by activity (Talk, Ode, Song) and then in separate folders for APS, CPC, and wav data. 

Data were processed using Igor Pro (v. 8.04, Wavemetrics). The data are available as a single zip file for download. All personal identifiers have been removed. 

File Structure for APS Data Files:

Line 1: The sample time for each spectrum, in seconds (here, 1 second)

Line 2: The assumed particle density entered in the AIM software, in g/cm^3

Line3: An indication of whether the Stokes correction was applied, off or on

Line 4: The lower bound size of the smallest particles bin, in microns

Line 5: The upper bound size of the largest particle bin, in microns

Line 6: The Sample Number

Line 7: The date of sample measurement (M/D/YYYY)

Line 8: The start time of the sample measurement, in local time

Line 9: First column = Aerodynamic Diameter label, Other columns = Raw Counts

Line 10-61: First Column = the bin-center particle aerodynamic diameter, in microns

Line 10-61: Other columns = the raw counts, in particles per sample time (here, particles/second)

Line 62-85: Ancillary information (not used)

File Structure for CPC Data Files:

Line 1: File name

Line 2: CPC Model

Line3: blank

Line 4: Sample Number

Line 5: Start Date

Line 6: Sample length

Line 7: Averaging time in seconds

Line 8: sample title

Line 9: Instrument ID

Line 10: Instrument errors

Line 11: Blank

Line 12: Average concentration (p/cm3)

Line 12: Minimum concentration (p/cm3)

Line 13: Maximum concentration (p/cm3)

Line 14: Standard deviation of concentrations (p/cm3)

Line 15: blank

Line 16: Column labels

  • Column 1: Elapsed time (seconds)
  • Column 2: Concentration (p/cm3)
  • Column 3: Analog signal 1
  • Column 4: Analog signal 2

An additional file is provided summarizing the data shown in Figures 1-3. All processed data have been summarized in one Excel file.