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Key Findings
- Measured noise levels at representative noise-sensitive receptor locations within the Study Area are consistent with levels expected within a mix of urban and suburban areas, where road traffic and industry are the dominant noise sources. These noise measurements include a daytime range between 48 dBA1 to 73 dBA and a nighttime range between 43 dBA and 70 dBA
- Typical ambient vibration levels measured at representative vibration-sensitive receptor locations within the study area range between 0.0067 mm/s2 and 0.0644 mm/s2 in theatres, 0.0826 mm/s (outdoor) at a recording studio and 0.016 mm/s in a hospital Magnetic Resonance Imaging (MRI) room. Current ambient vibration levels at these sensitive receptors are below the typical threshold of human perception
- Find out more: Noise & Vibration Information Sheet
1dBA refers to the noise level adjusted to how humans experience different frequencies. Typical ambient daytime noise levels — as experienced by humans — are 53 to 67 dBA in an urban area whereas a military jet take-off at 25 metres is 140 dBA.
2mm/s refers to ground-borne vibration velocity, where 0.1 mm/s is equivalent to 72 VdB or the approximate threshold for human annoyance, and 65 VdB (0.045 mm/s) is equivalent to the approximate threshold of human perception. VdB refers to the vibration level adjusted to how humans perceive vibration.
Noise Monitoring Equipment located at Wardell Street
Spotlight Case
The 3M Quest SoundPro noise monitor displayed in Image 2 measured sound levels at locations in the Study Area. Image 1 shows the noise monitor in a protective case at Wardell Street. Noise monitors provide advanced sound level monitoring and comprehensive data analysis. Noise monitors typically consist of an electronic device, preamp, microphone, windscreen to reduce sound disturbances and a digital display to view real-time frequency analysis. Typically, monitors are left in place for a specified duration (for this project, five days). Measurements are saved at select fixed intervals (for this project, every 15 minutes) which are stored in the device and then can be used to process and evaluate noise levels. The measurement data collected are provided in the Environmental Conditions Report. These baseline monitoring data can provide a benchmark for comparison with project noise impacts, which are predicted through various measurement and modelling tools.
Methods
Noise measurements were collected at 16 locations representative of noise sensitive receptors near the representative Initial Business Case (IBC) alignment. These locations – residential dwellings and places of worship – were selected based on proximity to the representative alignment and represent spaces and areas of human activity that are sensitive to noise.
Ontario Line: Noise Measurement Locations
Vibration measurements were collected at seven locations representative of vibration sensitive receptors near the representative IBC alignment. These locations - theatres, a recording studio and a hospital - were selected because they accommodate spaces and equipment that are potentially more sensitive to groundborne noise and vibration than typical residential buildings.
Ontario Line: Vibration Measurement Locations
Preliminary Potential Impacts & Mitigation Measures for Further Study | |
Construction | Operations |
Potential Impacts
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Potential Mitigation Measures
| Potential Mitigation Measures
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Future Studies
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Long-term construction noise monitoring station, with solar power and remote telecommunications
Noise logger capturing ambient noise