The harmonic-to-noise ratio (HNR) represents which of the following?

• A. The number of harmonics in a waveform
• B. The degree of acoustic periodicity
• C. The ratio between amplitude and frequency
• D. The difference between jitter and shimmer

Answer: (B)

Harmonic-to-noise ratio measures the balance between periodic, harmonic energy and non-periodic, noise-like energy in a voice signal, which reflects how acoustically periodic the sound is. A higher HNR means the voice signal is more periodic and clear, while a lower HNR indicates more noise and a rougher sound. So the best description is that it represents the degree of acoustic periodicity. It’s not about counting harmonics, the simple amplitude-to-frequency ratio, or the difference between jitter and shimmer, which are different concepts used to describe other aspects of voice quality.