[STM]– Changing voice with a free software

Have you ever paused to wonder what our human voices are really composed of? Is it possible changing voice from one person to another?

Beyond just the words we speak, each voice is a symphony of intricate elements working together. From the pitch that conveys emotion, to the unique timbre that makes each voice distinct, our vocalizations are rich with character. The speed at which we speak can shift the mood, while formants shape the very vowels we articulate. Add in resonance, volume, and even the subtle effects of modulation, and you’ve got a complex masterpiece. Each conversation is not just an exchange of ideas; it’s a beautiful interplay of sound, revealing layers of personality and emotion. Isn’t it fascinating to think about how much lies behind every utterance?

Table of Contents

Decomposition of human voice

Click on headings to learn about the components of human voice.

Pitch refers to the perceived frequency of sound. Higher-pitched voices have a higher frequency, while lower-pitched voices have a lower frequency. Adjusting pitch can make a voice sound higher (like a child) or lower (like a deep-voiced individual), which is useful for simulating different characters or genders.

Speed indicates how quickly the audio is perceived. Increasing speed results in a faster, higher-pitched voice, while decreasing speed produces a slower, deeper sound. Modifying speed affects both pitch and tempo, significantly altering the voice’s overall impression.

Timbre is the unique quality or color of sound that differentiates various voices or instruments, even at the same pitch and volume. Adjusting timbre can make a voice sound more nasal, breathy, or metallic, often through equalization and filtering effects.

Formants are the resonant frequencies in the vocal tract that shape vowel and some consonant sounds. Altering formants can change the perception of vowels and affect the voice’s characteristics, making it sound more feminine or masculine.

Volume refers to the loudness of the sound. While changing volume doesn’t inherently alter the voice’s characteristics, it can influence how other effects are perceived.

Resonance is created by the interaction between the voice and the shape of the vocal tract. Adjusting resonance can give a voice a more throaty, nasal, or clear quality.

Reverb: Adds echo or a sense of space, simulating a larger or smaller environment.

Echo: Produces repeated sounds at intervals for dramatic effect.

Distortion: Alters sound to create a rough or gritty texture.

Modulation involves variations in pitch, volume, or other elements over time. It can introduce vibrato or dynamic changes, making the voice sound more engaging or natural.

Noise reduction removes unwanted background noise or hiss, enhancing voice clarity and making changes more distinct and clean.

Changing voice in Audacity

Audacity is a free software to edit audio files. In Audacity, you can manipulate various components of your voice to change its sound. Here is a guide on how to adjust each component of voice using Audacity. The software can be downloaded here.

1. Changing Pitch

Adjust Pitch Without Affecting Speed:

Select Audio: Highlight the portion of the audio you want to change.
Navigate: Go to Effect > Change Pitch.
Adjust Pitch: Use the Percent Change slider or type in a value to increase or decrease the pitch. For example, +10% will raise the pitch, while -10% will lower it.
Preview and Apply: Click Preview to listen to the changes, and then click OK to apply.

2. Changing Speed

Adjust Speed Without Affecting Pitch:

Select Audio: Highlight the portion of the audio you want to modify.
Navigate: Go to Effect > Change Speed.
Adjust Speed: Use the Percent Change slider or enter a value to speed up or slow down the audio. Increasing the speed will also increase the pitch and vice versa.
Preview and Apply: Click Preview to hear the effect, and click OK to apply.

3. Adjusting Timbre Using Equalization

Modify Frequencies:

Select Audio: Highlight the portion of the audio you want to change.
Navigate: Go to Effect > Filter Curve EQ (or Equalization in older versions).
Adjust Frequencies: Use the curve to boost or cut specific frequency ranges. This can alter the timbre of the voice, making it sound more nasal, throaty, or clear.
Preview and Apply: Click Preview to check the changes, and then click OK to apply.

4. Manipulating Formants

Change Formants to Alter Voice Quality:

Select Audio: Highlight the portion of the audio you want to adjust.
Navigate: Go to Effect > Change Pitch. Check the Enable Formant Shift box.
Adjust Formants: Use the Percent Change slider to shift formants, which affects the vowel sound quality without changing pitch.
Preview and Apply: Click Preview to test the effect, and click OK to apply.

5. Adjusting Volume

Increase or Decrease Volume:

Select Audio: Highlight the portion of the audio you want to adjust.
Navigate: Go to Effect > Amplify.
Adjust Volume: Set the amplification level in decibels (dB). Positive values increase volume, while negative values decrease it.
Preview and Apply: Click Preview to hear the change, and then click OK to apply.

6. Applying Reverb or Echo

Add Space and Depth:

Select Audio: Highlight the portion of the audio to which you want to add effects.
Navigate:
- For Reverb: Go to Effect > Reverb. Adjust the parameters such as Room Size, Reverberance, and Delay Time to add echo and space.
- For Echo: Go to Effect > Echo. Set the Delay Time and Decay Factor to control the echo effect.
Preview and Apply: Click Preview to hear the changes, and then click OK to apply.

7. Reducing Noise

Remove Background Noise:

Select Noise Profile:
- Highlight a section of audio where only the background noise is present.
- Navigate: Go to Effect > Noise Reduction, then click Get Noise Profile.
Apply Noise Reduction:
- Select the entire audio or the portion you want to clean.
- Navigate: Go to Effect > Noise Reduction again. Adjust Noise Reduction, Sensitivity, and Frequency Smoothing to your preference.
- Preview and Apply: Click Preview to check the effect, and then click OK to apply.

By using these tools and effects, you can make substantial changes to your voice in Audacity. Experiment with different settings to find the combination that achieves the effect you’re looking for.