Data analysis
For hearing screening, the presence or absence of moderate or worse
hearing loss (PTA >40 dB) in each ear was determined by formal
audiometry, as 40 dB is considered the critical hearing threshold for
disabling hearing loss according to the World Health Organization,
and warrants further investigation.
The iPhone uHear PTAs in all three settings were compared with
the formal audiogram PTAs, where the PTA is calculated as a mean
of thresholds (hearing in dB) at 500, 1 000, 2 000 and 4 000 Hz. These
data were captured into 2 × 2 tables to calculate sensitivity, specificity
and accuracy ratios.
Additionally, in view of the possibility for agreement by ‘chance’,
kappa analysis was performed on iPhone thresholds from all three
settings when compared with the formal audiogram to detect
agreement at all six frequencies. Kappa values range from