Tech Tip Thursday from Facebook

Most audio software, such as Cool Edit and Adobe Audition, have a "hard limiting" option. This can be used to control the relative loudness between quiet and loud sections of an audio file. Hard Limiting can boost quiet sections and simultaneously reduce louder sections (like the investigator speaking normally).

It is easy to make the mistake of merely "boosting" (adding amplitude) to an audio file to "bring out" the quiet parts. While this *does* amplify the quiet parts, it also boosts the loud parts as well. This can often lead to "clipping" (a nasty-sounding distortion) when a louder sound is encountered.

Hard Limiting (or an equivalent feature with another name) not only is able to limit the maximum amplitude (loudness) of an audio clip (thereby preventing clipping), but can also selectively amplify only the quieter sections. This reduces the dynamic range (the difference between the louds and the quiets). This makes it possible to listen for EVPs without worrying about going deaf when a louder sound occurs on the audio.

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