Overview:

One source of freshwater was the nearby Ellerbee Creek in North Carolina. Recordings at this site, the portion between W Knox St and Washington St in Durham, were done in order to capture some of the dynamic parts of a moving body of water. The soundscape both above and underneath the surface was recorded. The environment present in the area was rather diverse for such a small-scale setting. There were birds and other organisms in the area, such as insects and trees, and a variety of sounds can be heard just by standing and listening. However, a diversity of sounds underneath the surface should also have been obtained, as care was taken to choose locations of varying stream flow.

This should compare nicely to the much less urban surroundings of the water sources in Puerto Rico, and also to Lake Crabtree, as it is a much larger and stiller body of water. Comparing and contrasting the different impacts of the external forces on the underwater soundscape in these different settings will lead to a better idea of how these water soundscapes are affected. Also, looking at the nature of the bodies of water and the role it plays in shaping the overall soundscape, both above and below the surface, will give a better idea about the big picture of freshwater aquatic soundscape.

Before we go further, now would be a good time to make the point that "water sounds" and "sound in water" are two quite different descriptions. "Water sounds" can also be rephrased as "sounds of water", and refers to the sounds of water that we hear every day, generally above the surface. The faucet is an example of a "water sound", and so is the splashing of water in a pool or a bathtub. On the other hand, "sound in water" refers to the sound as it sounds underwater. If you were to submerge yourself and drop a coin into the water, the sound of the coin hitting the water would be a "sound in water", as the frame of reference is now underneath the water and in water. Essentially, "water sounds" refers to sounds water makes in the soundscape of air (as we would hear them) and "sound in water" refers to sounds that occur in water. 

A somewhat calm area with relatively little water flow was selected, and the recording done there. There are many sounds on the outside, and the soft bubbling of the water should be heard underneath.

This above recording is the soundscape above the surface. There are some bird calls to be heard, and overall the sounds do not seem to "stick out" or otherwise interrupt the soundscape; they seem to be a natural part of the above water soundscape mesh.

This is the underwater soundscape at this particular location. Since this area was one in which the water was actively flowing into the hydrophones, static-like sound can be heard when this happens. Note that all of this is very gentle. 

The above is the combined recording of the two, and the effect could be described as if you would place your ear in the water such that half of your ear is submerged and the other half is above the surface. This, however, is not the best description possible. It is very difficult to describe what the combining of these two recordings actually represents. The hydrophones do not exactly replicate what we as humans perceive underwater, although it is doubtful that many people actually pay attention to this. In this specific case, you can hear the distinctive bird calls paired with the somewhat frequent water moving underneath.

An area of very shallow water flowing over the rocky bottom was selected, and recording performed there in order to hear the sounds of a quickly flowing creek.

This above recording is the soundscape heard above the surface. There are some bird calls, some sort of bumping noise, and a general white noise due to the flow of the creek in the background. The sound of the creek is not that loud.

There is a significant amount of static-like noise that can be heard. This would be all of the water trickling over the rocks. The hydrophones were also bumping quite a bit due to the quick flow of the creek water.

This is the combined recording of the two. The underwater sounds can be heard on top of the above water soundscape. The two together seem to give a holistic picture of the overall soundscape at this location. Notice that the lack of a distinct set of "water sounds" on the outside of the aquatic soundscape does not suggest that the aquatic soundscape is not active or is "uninteresting".

A very calm, relatively deeper area of the creek was chosen. The area is seemingly dead, and what the water actually sounds like underneath will be described. 

By now, the birds are really into it, and what seems to be a call-and-response between possibly a couple (if you listen closely, the call and the response are unique). They and other wildlife sounds are very prevalent in this natural soundscape.

Since is this a very calm and somewhat deep area, there is not much going on in terms of the underwater soundscape. All is well and tranquil.

This is the combination of the above two recordings. It is rather difficult to hear the aquatic sonic environment, although if you pay very close attention sometimes you can pick up an occasional movement. This also gives rise to an interesting point: the water seems to act as a thick shield, difficult to penetrate, as the underwater soundscape seems to be completely insulated from the diverse range of sounds taking place outside.