According to the sampling theorem, it is impossible for a digital recorder to properly record any frequency higher than half of the recorder's sampling frequency (called the Nyquist frequency). Any information above the Nyquist frequency is therefore removed in the process of recording.

Note that the file size of recordings scales directly with sampling rate, so it's not necessarily a good idea to choose the highest sampling rate available on your recorder. Determine the highest frequency you are interested in among your species of interest, including harmonics, and choose the lowest sampling rate greater than twice that frequency in order to save on storage space.

• What is the lowest frequency the Song Meter Mini Bat's ultrasonic microphone can record?
• What is the lowest frequency the Song Meter SM4BAT FS can record?
• Why can't I use an adapter to connect a USB-C Echo Meter Touch to my Lightning iOS device?
• What iOS devices are compatible with my Echo Meter Touch module?
• Can I use Echo Meter Touch modules with USB connectors with iOS devices?
• What type of plug does my Echo Meter Touch module have?
• What type of data port does my phone or tablet have?
• What adapter do I need for my Echo Meter Touch module and Android or iOS device?
• How do I update the firmware on my Echo Meter Touch module with USB to add iOS compatibility?
• Are there acoustic differences between the first- and second-generation Mini Bat recorders?
• Will the Lithium-ion lids I used with first-generation Minis fit the new models?
• Will the security bracket accessory I use with first-generation Minis be compatible with the new models?
• View more questions