Although a sound wave's frequency determines its pitch, variation in human abilities and sound distortion determines what is actually heard. According to Stevens' Rule, people hear an increase in pitch when the original pitch is greater than 2 KHz and volume is increased, but the opposite is true for pitches lower than 2 KHz. If you're a true audiophile that must have perfectly consistent pitch, Windows Media Player has a native tool you'll appreciate. The Graphic Equalizer adjusts frequencies at varying intensities to fine-tune the perceived pitch. This enables you to overcome the Stevens' Rule at varying volumes; alternatively, you can change the pitch without changing the volume.
Open the audio or video file in Windows Media Player. If the file is playing in the Library window, click the bottom-right "Switch to Now Playing" button.
Right-click anywhere in the Now Playing window, point to "Enhancements" and then select "Graphic Equalizer."
Select the graphic mode you prefer, such as individual adjustments or loose/fine groups. The icon next to the selection describes it, and a textual description appears if you hover your mouse pointer over the option.
Click and drag the sliders to change the pitch. You might notice the greatest effect around the 2 KHz slider, but what produces the most effect varies between people.
Click the small "X" at the top right of the Graphic Equalizer pop-up to close the utility.