russellsh2 wrote:I am looking for a device that I can use to pickup sound, and show what sound it has sensed on a display like a spectrum analyzer. however the range needs to be from normal human hearing range to say 40khz. i am not interested in software for my phone or computer because these devices are designed for human hearing.
If you want a spectrum-analyser display then you only have two choices: you either go down the computer/tablet/phone route, or you buy a professional laboratory spectrum analyser hardware unit!
The latter will cost as much as a car... so your only sensible option is to go down the computer app route in one form or another.
As has been said, you will need to make sure your sound-capturing device is capable of working across the full range you want. Conventional mics all tail off by 25kHz and most are lower, but there are mics that will reach up to 40 or 50kHz, and some that can reach 100kHz. Check out the offerings from Earthworks and Sanken, for example.
You could use these mics with a decent computer interface capable of running at a 96 or 192kHz sample rate, ensuring a bandwidth up to a nominal 48 or 96kHz, respectively, and then use a programme like Adobe Audition which has a spectrum analyser to reveal what's going on.
None of this is cheap... though.
On the other hand, a more affordable and possibly more practical alternative might be to use a bat-detecting system, such as EchoMeter Touch 3 which works with iOS devices (iphones or ipads etc) or Android devices, and gives a spectral display derived from its own plug-in mic unithttps://www.echometertouch.com/
There are a lot of different bat-detector systems around -- that one is just one I happen to be vaguely familiar with.