Is it possible to filter hiss background audio?

I used a Flip Ultra HD which has an excelent audio quality. Now I bought a Sanyo SH1 which records audio which some background "hiss" audio (shame on Sanyo, bad built-in microphone).

Is there a way to remove the background "hiss" audio in Kdenlive? It seems sox can do that:

noiseprof [profile-file]

noisered profile-file [threshold]
Noise reduction filter with profiling. This filter is moderately effective at removing consistent background noise such as hiss or hum. To use it, first
run the noiseprof effect on a section of silence (that is, a section which contains nothing but noise). The noiseprof effect will print a noise profile to
profile-fire-fR, or to stdout if no profile-file is specified. If there is sound output on stdout then the profile will next be directed to stderr.

To actually remove the noise, run SoX again with the noisered filter. The filter needs one argument, profile-file, which contains the noise profile from
noiseprof. thershold specifies how much noise should be removed, and may be between 0 and 1 with a default of 0.5. Higher values will remove more noise
but present a greater possibility of distorting the desired audio signal. Experiment with different threshold values to find the optimal one for your
sample.

Theoretically, yes, it is possible. Practically speaking, though, it is not possible now due to difficulty to integrate the special needs of this sox effect into the GUI. So, you really should do this in a separate tool and use result as an audio clip in Kdenlive.

I would love it if there was a Noise/Hiss remover. Is it easier to implement now in the new version of kdenlive? which has gotten some what of a GUI overhaul, or is the problem with the sox filter itself not being GUI friendly at all?

Any other Noise/Hiss reduction out there worth implementing?

Pretty much every video I make has this high pitch tone in the background(due to my mic).

[edit]: added the text below

Most of my videos are somewhere around 2-6 hours(video game play), and I've tried extracting the audio and processing it with Audacity, which just seem to fail most of the time(below 2 hours is usally no problem). But I know from experience that kdenlive never fails on me when it comes to lengthy audio processing(Normalize).

I'd really like it if I only needed one tool(kdenlive) to make videos.