BC Rapid Transit Company March 11, 2026
OMCI Simulation Room Noise Survey - 6 - 2044.20383.2026

3. Permanent threshold shift

a. When exposure to noise occurs over a long period of time or without
sufficient recovery periods between exposure, causing temporary threshold
shift to become permanent.

In addition to NIHL, exposure to noise can lead to tinnitus. Tinnitus is a ringing, hissing,
or humming in the ears that is present even in the absence of external acoustical stimuli.

Hearing loss can impact an individual both physically and psychologically. Physical effects
may include sleep disturbance, balance disturbance, an increased heart rate, and narrowing
of blood vessels. Psychologically, hearing loss can lead to reduced concentration, social
isolation, anxiety, stress, and reduced motivation.

NIHL can place a worker at increased risk while at work due to a loss of ability to localize
sound sources, perceive acoustical warning signals, and impairment of verbal
communication.

5 OBSERVATIONS

The training room is located on Level 2 of the Operations and Maintenance Centre 1. The
room contains three rows of desks equipped with computers, monitors, and speakers
configured for simulation training. Two server racks are located at the southeast corner of
the room, approximately | meter from the nearest computer simulation desk.

During the noise survey, no training sessions occurred inside the room. The computers and
monitors were operational and idling in the background, with occasional intermittent
computer notification sounds emitted from the speakers. The HVAC system was operating
under normal conditions. The two server racks were also operating normally, producing a
steady, continuous operating noise.

Spot noise measurements were collected at several locations inside the training simulation
room and an office space outside of the room for comparison purposes.

For data logging, the sound level meter was stationed by the simulation desk, adjusted to
the same height as a person sitting on a chair. The sound level meter continuously logged
for approximately 9 hours.

BCRTC representative reported there were no other work activities occurring in the room
except maintenance personnel who had to check on the server equipment by opening and
closing the server rack doors.

Arcose Consulting Ltd.