Zero-Crossing (ZC) is a legacy method of recording bat vocalisations that was used before recording high frequencies in full-spectrum was practical, and it is still used in applications where data storage space is at a premium. Rather than recording wideband audio, ZC recorders take measurements of an incoming audio signal’s most prominent frequency at a given time. ZC recordings do not contain amplitude information, nor can they represent multiple frequencies at any point in time. This means that wideband signals such as harmonics, overlapping calls, and faint signals in the presence of background noise are lost. This also means that the resulting recordings take up very little data space.

In the spirit of reconciliation, Faunatech acknowledges the Traditional Custodians of Country throughout Australia and their connections to land, sea and community. We pay our respect to Elders past and present and extend that respect to all Aboriginal and Torres Strait Islander peoples today.