WORKING TO MAKE A DIFFERENCE

Memo
(continued)

Worker last name First name Middle initial WorkSafeBC claim number
HOLAND MARK 42647461

This conclusion fails to address the clinical significance of asymmetry.

My post-incident audiogram from January 30, 2026 shows a 10dB threshold shift
specifically at 8kHz in my left ear relative to the September 2025 baseline. This shift
is unilateral and frequency specific. It is not distributed evenly across both ears or
across all frequencies.

Asymmetric threshold shifts are clinically significant precisely because they indicate
a specific unilateral acoustic event rather than bilateral age related change or test-
retest measurement noise. The clinical literature consistently identifies asymmetric
sensorineural hearing changes as requiring further investigation regardless of
magnitude.

Flora Pang dismissed the shift as within variability without addressing the
asymmetry. A complete clinical opinion on an auditory injury claim must address not
only the magnitude of threshold change but its laterality and frequency specificity.
The 10dB asymmetric shift at 8kHz in the left ear — the ear | consistently reported
as more severely affected — was dismissed without adequate clinical analysis.

ERROR 4 — UNCRITICAL ACCEPTANCE OF COMPROMISED ACOUSTIC
DATA

The clinical opinion states the noise measurements were collected using
appropriate equipment and analyzed by professionals trained and experienced in
noise measurement methodology and accepts the Arcose data without qualification.
The Arcose Consulting Ltd. noise survey has been formally challenged in my
WorkSafeBC Supplementary Submission dated March 19, 2026, identifying six
independent methodological deficiencies. These include:

The survey was conducted March 6, 2026 — 53 days after my injury date and after |
had already been absent from the workplace for five weeks. The acoustic
environment was not assessed during the period of my exposure.

The survey used broadband A-weighted measurement. The TSI SoundPro DL-1
instrument used by Arcose is capable of 1/3 octave band analysis and speech
intelligibility testing. Neither capability was utilized. Broadband A-weighted
averaging mathematically masks frequency-specific energy. A resonance source
producing elevated output at a specific frequency may not be detected by
broadband averaging even if that frequency-specific energy is physiologically
significant.

Arcose was not provided with my Acoustic Trauma Brief, my audiogram, my clinical
diagnosis, or my WorkSafeBC claim information when commissioned. This has
been formally documented in my January 27 witness statement submitted March
18, 2026. The consultant assessed a standard broadband noise exposure question
rather than a frequency-specific clinical exposure question because the clinical
context was withheld from them by the commissioning party.

The Arcose report was commissioned by Austin Puder, Senior Manager Train
Operations — the same manager who was informed of my ear injury in person on
January 27, 2026, with a union representative present, and who subsequently told
me to take it to WorkSafeBC. His knowledge of my injury prior to commissioning
Arcose is documented in my formal witness statement submitted March 18, 2026.
A clinical opinion that accepts without qualification acoustic data produced under
these conditions has not applied appropriate scientific scrutiny to its evidentiary
base.

68B33

(R01/09) Page 3 of 9