What is Vocal Resonance in Singing?

Vocal resonance in singing is the amplification and enrichment of the raw sound produced by your vocal folds as it travels through the air-filled cavities of your vocal tract.

Think of it this way:

1. The Source (Vocal Folds/Larynx): Your vocal folds vibrate to create an initial, buzzy sound.¹ This sound itself isn't particularly loud or rich; it's more like the sound of a buzzing bee. It contains a fundamental frequency (the perceived pitch) and many higher frequencies called overtones or harmonics.

2. The Filter/Resonator (Vocal Tract): This is where resonance happens. Your vocal tract is the series of interconnected tubes and chambers above your vocal folds, including:

   • Pharynx: The throat cavity.

   • Oral Cavity: Your mouth.

   • Nasal Cavity: Your nose and sinus passages.

     
     

These cavities act like acoustic filters or resonators. Just as blowing across the top of a bottle at the right pitch makes the sound amplify, your vocal tract selectively amplifies certain frequencies (the overtones) that naturally align with its own resonant frequencies.

Full resonance means that the vocal tract is optimally shaped and free from constriction, allowing for the most efficient amplification of the vocal fold sound. This results in a voice that feels:

• Effortless to produce: The sound "carries" without pushing.

• Rich and vibrant: It has a pleasing complexity and depth.

• Clear and focused: It has "ping" or "ring" (often called "squillo" in classical singing), making it cut through other sounds.

  
  

• Consistent in quality: The tone remains stable and resonant across your entire vocal range.

Sensations like "singing in the mask" and "open throat singing" are often experienced when a singer is achieving good vocal resonance, as they indicate appropriate shaping and relaxation of the vocal tract.

Can Resonance Be Seen on a Spectrogram?

Yes, absolutely! Spectrograms are a primary tool for visualizing vocal resonance.

A spectrogram plots sound in three dimensions:

• Time: Horizontal axis (x-axis).

• Frequency: Vertical axis (y-axis), representing pitch from low to high.

• Amplitude (loudness/intensity): Represented by the brightness or color of the display.

  
  

When you look at a spectrogram of a sung or spoken sound:

• You'll see horizontal lines, which are the harmonics (or overtones) produced by the vocal folds. The lowest line is the fundamental frequency (the perceived pitch).

• You'll notice brighter or darker bands that cut across these harmonics. These are the formants. Formants are the actual resonant frequencies of your vocal tract.

  
  

How resonance appears on a spectrogram:

When a voice has good resonance, you will see:

• Prominent, strong, and well-defined formants: These appear as distinct, bright bands on the spectrogram, indicating that specific frequency regions are being strongly amplified by the vocal tract.

• A rich and balanced distribution of energy: While formants will highlight certain frequencies, a well-resonated voice will typically show energy across a broad spectrum, making the sound full.

  
  

• Consistent formant patterns for sustained vowels: If a singer maintains good resonance on a vowel, the formant structure will appear stable.

• The "Singer's Formant" (or "Ring"): For classically trained singers, especially males, a particularly strong cluster of formants often appears around 2500-3500 Hz. This specific resonance is highly prized for its ability to make the voice "ring" and project over an orchestra, and it is clearly visible as a bright band in that frequency range on a spectrogram.

Does Good Resonance Mean Having Many Higher Harmonics or Overtones?

This is a crucial point of clarification:

• The vocal folds produce the harmonics/overtones. Even a poor vocal sound will have some harmonics. The efficiency of vocal fold closure and vibration (how well they come together) influences the initial strength and presence of these harmonics. A clear, strong vocal fold closure tends to create a richer harmonic series from the start.

  
  

• Resonance (the vocal tract's role) doesn't create new harmonics. Instead, it selectively amplifies the harmonics that are already present in the vocal fold sound. It acts as an acoustic filter, boosting the harmonics that align with its own resonant frequencies (formants).

  
  

So, while a voice with "full resonance" will sound rich in overtones because certain ones are powerfully amplified, it's more accurate to say that good resonance is about the efficient amplification and shaping of the existing harmonics by the vocal tract.

A voice might produce many harmonics at the vocal fold level, but if the vocal tract isn't shaped optimally for resonance, those harmonics won't be efficiently amplified, resulting in a weaker, less vibrant, or "swallowed" sound. Conversely, a voice that effectively utilizes its resonators can make a relatively "small" vocal fold sound project with great power and richness.