Question on changing range of y axis


I am using audacity to view .wav files that I have recorded from a bat recorder attached to a digital audio recorder. I want to view the y axis as kHZ if possible and for a range from 0-100kHz. I can’t seem to figure out how to change the y axis range. I first changed the vertical scale for the range I wanted. The, I tried the advanced mode vertical zooming to have it display the full range, but it only showed about 0-11kHZ. Not sure why it was getting cut off. Any help is much appreciated. Thanks!

Are you referring to the “spectrogram” track view? (

The upper frequency range of digital audio is limited to half the sample rate (called the “Nyquist frequency”). My guess is that your digital recorder was recording with a sample rate of 22050 Hz, which is adequate for speech recordings, but far too low for recording bats. To be able to record frequencies of 100 kHz, the sample rate must be at least 200 kHz.

There are some semi-pro recorders, such as the Tascam DR-100 MKIII (about $300), that can record with sample rates up to 192 kHz, which will give a theoretical upper frequency limit of 96 kHz, but in practice the frequency limit is likely to be significantly lower. For higher sample rates, you will be looking at specialist equipment that will probably be very expensive.

One commonly used way to record bats, is to use a “bat detector”, which electronically lowers the frequency of the bat’s sound, so that it can be recorded (somewhat artificially) with reasonably priced consumer level equipment.

There are quite a few resources available on the Internet about recording bats (and other sounds of nature). Here’s a couple of links from Google:

Thanks for the input. I do use a bat detector (Batbox Duet) hooked up to a DGFAN Digital Voice recorder. It does lower the frequency and I am able to use the accompanying software from Batbox to see the scans. However, the program is limited so I was looking for another program to use with more ease and I work through the file. Thanks for the explanation on the sample rate. That explains the issue I am having. I will look into some of the websites you suggest to see if I should make any modifications to my equipment depending on cost.