  Optical frequency comb-referenced measurements of self pressure-broadened
line profiles of the R(8) to R(13) lines in the \thisband combination band of
acetylene near 1.52$\mu$m are reported. The analysis of the data found no
evidence for a previously reported [Iwakuni et al. \textit{Phys. Rev. Letts.}
\textbf{117}, 143902(5) 2016] systematic alternation in self pressure-broadened
line widths with the nuclear spin state of the molecule. The present work
brought out the need for the use of an accurate line profile model and a
careful accounting for weak background absorptions due to hot-band and lower
abundance isotopomer lines. The data were adequately fit using the quadratic
speed-dependent Voigt profile model, neglecting the small speed-dependent
shift. Parameters describing the most probable and speed-dependent
pressure-broadening, most probable shift, and the line strength were determined
for each line. Detailed modeling of the results of Iwakuni et al. showed that
their neglect of collisional narrowing due to the speed-dependent broadening
term, combined with the strongly absorbing data recorded and analyzed in
transmission mode were likely the reasons for their results.
