  The introduction of ISO 12913-2:2018 has provided a framework for
standardized data collection and reporting procedures for soundscape
practitioners. A strong emphasis was placed on the use of calibrated head and
torso simulators (HATS) for binaural audio capture to obtain an accurate
subjective impression and acoustic measure of the soundscape under evaluation.
To auralise the binaural recordings as recorded or at set levels, the audio
stimuli and the headphone setup are usually calibrated with a HATS. However,
calibrated HATS are too financially prohibitive for most research teams,
inevitably diminishing the availability of the soundscape standard. With the
increasing availability of soundscape binaural recording datasets, and the
importance of cross-cultural validation of the soundscape ISO standards, e.g.\
via the Soundscape Attributes Translation Project (SATP), it is imperative to
assess the suitability of cost-effective headphone calibration methods to
maximise availability without severely compromising on accuracy. Hence, this
study objectively examines an open-circuit voltage (OCV) calibration method in
comparison to a calibrated HATS on various soundcard and headphone
combinations. Preliminary experiments found that calibration with the OCV
method differed significantly from the reference binaural recordings in sound
pressure levels, whereas negligible differences in levels were observed with
the HATS calibration.
