Dataset DOI: 10.5061/dryad.bg79cnpr6

Description of the data and file structure

Deployment Description:

A hydrophone (described below) was deployed 1 m above the seabed on an Teledyne Oceanscience Sea Spider. The unit was oriented vertically (i.e., the long-axis of the housing was perpendicular to the seabed) with the hydrophone facing the surface. The unit was deployed 30' (9 m) from the center of the 30 m berth at the Wave Energy Test Site (Kaneohe, HI). Rock drilling was performed approximately 10 m from the hydrophone while rock drilling and chipping were performed approximately 90 m away.

Drilling was performed using a Stanley SK-58 Sinker Drill (model SK58310) equipped with a 4.44 cm (1-3/4”) Stanley carbine tipped Rok-bit. A Stanley BR-45 Hydraulic chipper (model BR45350) equipped with a Stanley 15.24 cm (6") moil point chipping bit was used to flatten the rock surface.

Hydrophone specifications:

Model: HTI 96-min

Sensitivity: -176 dB re V/uPa

Amplifier gain: 0.6 dB

DAQ Voltage: +/- 0.935 V

Sampling frequency: 96 kHz

File duration: 5 minutes

Logger: Loggerhead Instruments LS1X autonomous hydrophone/recorded

Files and variables

File: Audio.zip

Three audio (.wav) files have been included. The two files (one each for drilling and chipping) are the same files used to create Figure 2 in the manuscript. The third audio file contains an example of audio with saturated signals from drilling measured at a short range.

Filename: 20220119T203812.wav

Description: This is a five-minute audio file containing drilling noise from work performed at site MK, roughly 90 m from the hydrophone's location.

Filename: 20220119T203812.wav

Description: This is a five-minute audio file containing chipping noise from work performed at site MK, roughly 90 m from the hydrophone's location.

Filename: 20220118T233109.wav

Description: This is five-minute audio file containing drilling noise from work performed at site MC, approximately 10 m from the hydrophone's location. This file contains a significant number of signals from drilling that were clipped due to the intensity of the noise and the hydrophone's sensitivity. In addition, high-frequency signals from an echosounder are present as a constant background noise. In contrast to the work at MK, a support vessel was located directly above the location where the work was being performed.

File: Drilling_and_chipping_metrics.mat

This .mat file contains a broad range of consolidated data outputs as vectors and structures. These are each described below. Note the following abbreviations are used in variable names or descriptions Units are denoted in square brackets:

• psd (or PSD): Pressure spectral density [dB re 1 uPa^2^/Hz]
• TOL: Shorthand for sound pressure levels in decidecade bands [dB re 1 uPa]
• pcrf: Used to variables with probability density functions

Variables

"f": A vector of frequencies [Hz] corresponding to hybrid millidecades used to plot spectra.

"ftol": A vector of center frequencies [Hz] for all calculated decidecade bands (12.5 Hz to 25 kHz)

"lims": Limits to bins used to calculate empirical probability distributions for noise metrics (range from 40 to 160)

"C": A structure containing data that corresponds only to active chipping activities at site MK (~90 m).

There are a total of 1032 entries corresponding to 1032 1-s periods with active chipping at the site. The C structure contains the fields/variables:

"C.psd": Pressure spectral densities for 1 sec windows, use with variable f for plotting against frequency

"C.TOL": Decidecade SPLs for 1 sec windows, use ftol for plotting against center frequency band

"C.BB": BB SPLs calculated in 1 sec windows

"C.prcf": Probability density functions for PSD using the bins from 40 to 160 with 1 dB resolution

"C.TOLprcf": Save as C.prcf except with decidecade SPLs

"C.per": PSDs corresponding 95, 75, 50, 25, and 5% exceedance thresholds.

"C.perTOL": Same as for C.per except for decidecade SPLs

"C.perSL": Calculates acoustic source level [dB re 1 uPa @ 1 m] using the 95, 75, 50, 25, and 5% exceedance thresholds

"C.TOLSL": Same as C.perSL except source levels are calculated in decidecade bands

"C.BB1to25k": Broadband SPLs from 1-25 kHz corresponding to the 95, 75, 50, 25, and 5% exceedance thresholds

"C.BBAll": Broadband SPLs calculated across all decidecade bands corresponding to the 95, 75, 50, 25, and 5% exceedance thresholds

"D1": A structure containing data that corresponds only to active drilling activities at site MC (~10 m).

The fields otherwise match those for C except the primary variable is D1 (e.g., D1.psd)

"D2": A structure containing data that corresponds only to active drilling activities at site MK (~90 m).

The fields otherwise match those for C except the primary variable is D2 (e.g., D2.psd)

"Ambient": A structure containing the mean PSD and decidecade SPLs measured during overnight periods (1900-0500 local time)

"Ambient.PSD": pressure spectral densities [dB re 1 uPa^2^/Hz]

"Ambient.tol": Decidecade SPLs [dB re 1 uPa], can be plotted against ftol

"Ambient.f": Frequency [Hz] array to use with the ambient data

Note that in structures C, D1, and D2 indices for decidecades with center frequencies below 100 Hz have been given a NaN value. This is because the spectrograms corresponding to active drilling and chipping were calculated using 1 s averages of windows calculated with 0.1 s resolution and thus have 10 Hz resolution. The resolution of these data are therefore too low to resolve the low-frequency data.

File: WETS_DrillChipUnweighted_PSD_ChippingandDrilling.mat

This .mat file contains 0.1 s resolution pressure spectral densities associated with rock drilling and chipping activities measured at approximately 90 m. The pressure spectral densities can be integrated to calculate unweighted sound exposure levels, or auditory weightings can be applied to evaluate weighted sound exposure levels. Millidecade band merging was used to compress the data volume. The data focuses exclusively on work windows with drilling and chipping activities starting immediately. Each time series continues until the work window concludes (approximately 45 minutes for chipping and almost 2 hr 45 min for drilling). Thus, the time series includes natural gaps where activities pause.

Variables

"freq": A vector [1478 x 1] containing a vector of frequencies [Hz] corresponding the PSD variables

"PSD.drill": An array [1478 x 96931] contains pressure spectral density values [dB re 1uPa^2^/Hz] associated with rock hammer drilling.

"PSD.chip": An array [1478 x 26606] contains pressure spectral density values [dB re 1uPa^2^/Hz] associated with rock chipping.

"time.drill": A vector [1x96931] noting the duration since the beginning of drilling activities.

"time.chip": A vector [1x26606] noting the duration since the beginning of chipping activities.

"dt": A variable denoting the length of each window used to calculate the pressure spectral densities (0.1 s).

"notes": Character string noting that the variable PSD represents the pressure spectral density, which corresponds to L_p,f in the associated manuscript.

Code/software

The .mat files were exported using Matlab R2023b.

File: Figure4.m

This file contains a script that can be used to plot the the variance exceeding thresholds for PSDs, decidecade SPLs, and ambient noise conditions at night. With minor formatting modifications this matches Figure 4 in the companion paper. The variables match those included in Drilling_and_chipping_metrics.mat.

File: SoundExposureCalculations.m

This file can be used to load the 'WETS_DrillChipUnweighted_PSD_ChippingandDrilling.mat' file and performs example unweighted and M-weighted sound exposure calculations by applying the relative weights, integrating the spectra, and summing the temporal-domain results.

Access information

All data was derived from the measurements described in the paper. No external sources of data were used.

Additional audio files are available upon request.