Equipment used

Zoom Recorder

For this project we used two different types of microphones to get our case study recordings. The first a zoom microphone which is pictured below:

 

 

 

 

 

 

 

 

 

 

 

 

This was used for above water sounds, and acts as a typical recorder (the way a recorder on a phone might act). It is also important to note that due to the advantages of digital recordings, the amplification of sound in these recordings resulted in sound that was still clear. If analog recordings had been utilized, amplification would have resulted in a dramatic increase of noise, both physical and digital, resulting in static and distortion of sound. 

 

Hydrophone

The second, lesser known type of recorder used was a hydrophone (pictured below):

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

This is the JrF D-series hydrophone that was used. The way the hydrophone works is by use of a piezoelectric speaker. A piezoelectric speaker is a thin, round metal disk with a “piezo material” (usually some type of crystal, but can also be ceramics) at its core. In its essence, a piezoelectric speaker works through the rapidly changing shape of a crystal such as quartz to produce vibrations.  The crystal changes shape in response to voltages put through it, and depending on the voltage applied, the crystal will change to different shapes (Brown, et. Al  1).Thus, when the water hits the hydrophone it acts as the voltage/pressure source and the speaker (hydrophone) reacts in such a way to produce sound.  The sounds produced by this recorder, thus are not like the stereo sounds, but instead record only the sounds of the materials touching the recorder in the medium (for this reason, a hydrophone does not work well in air). It is worth noting, thus, that the sounds recorded by the hydrophone (as any microphone to some extent) are not perfect representations of the sounds in nature. Likewise, the editing of these sounds (amplification) causes the noise present in the sound to also be amplified. Especially in some of the recordings, this noise may play a disproportional role in the recording in order to allow the water sounds to be heard at all. All amplifications are stated in the description of the audio.

 

 

Brown, Collins, Connley, Gustafon, Huettel, Kim, Tantum, and Ybarra. 2015. “Laboratory VI Light-Controlled Tone Generator.” ECE 110L Laboratory Manual: Fundamentals of Electrical and Computer Engineering. 1—11.