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Converting sound to ultrasonic


I need to convert a bird sound from the audible level to the ultrasonic,  close to the the 20khz level. as long as we human cant hear the sound.  My question is,  what is the best method to convert this file?

thanks in advance

Xray_Man2 years ago
WHY do you want to convert and audible sound to ultrasonic? Usually, it's done the other way around. For example, people who study bats use a device that converts their ultrasonic "echo location" sounds to the audio range that humans can hear. So, what you are asking for doesn't make sense unless you have a very special reason for doing it that way. Please explain...
gmoon3 years ago

Audacity , the cross-platform audio editor has several plugins that might help.

The "Change Pitch" tool will alter pitch without changing the tempo...i.e., the audio sample will be the same length after the change. It takes some heavy algorithms to achieve this, so complex music files sometimes sound a little off after the conversion (beat frequency interactions and such).

That has something to do with the nature of pitch being non-linear. The tool lets you fine-tune the changes by semitone, etc. This may or may not be an issue with a simple monophonic "voice" file.

Audacity can also easily change the speed, which would raise the pitch but also shorten the duration.

A typical speaker might not be the right type of transducer to reproduce ultrasonic frequencies...
bujuk (author)  gmoon3 years ago
thank you gmoon for the tips.

yeah, i'm working on audacity and i'm aware about the pitch functionality. unfortunately there are tons of audacity menus and options that i need to understand.

thanks again
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