Build a hydrophone
While it is possible to build a hydrophone for as little as $20, it is more efficient and enjoyable to buy a hydrophone readily available model to suit your needs. This is because they are quite inexpensive for a basic model and their performance will be far superior to home-made versions. Typical hydrophone prices range between $40 to $3000 depending on the needs. Purchase of a commercially made hydrophone will offer you greater satisfaction and sound quality from your hydrophone recordings. If however, you do fancy the challenge to make build a hydrophone of your own, there are plenty of instructions to build your own using simple online search. These plans tend to use everyday items found around the home. Or, if you want a bespoke professional device, try this one from NOAA charts:
Although it is not considered necessary for the effective operation of a hydrophone, the use of software linked to a computer will enable the user to ‘see’ what is being recorded, although many manufacturers offer free software included in the purchase of their hydrophone systems (even if choosing their cheaper, budget hydrophone options). It would also be beneficial for your self build a hydrophone to obtain suitable software. What seem ordinary sounds to the common ear are in fact complex combinations of individual harmonics producing a wide range of frequency and intensity this will be easier to digest with such software.
The addition of a spectrogram simply plots the frequency components of such an audio signal, displaying it as a moment of given time. Spectrogram programs are digital audio recordings typically using .WAV format that are analysed by using frequency versus time and displayed using a variable colour scale. spectrogram can show the hidden frequency structures of an audio signal and can also be used to identify or classify particular sounds.
When choosing a commercially bought hydrophone, most retailers can supply the software along with the hydrophone purchase. This is something you should take advantage of for a fully comprehensive experience in capturing your hydrophone recordings.