What aspect of speech does a spectrogram represent visually?

• A. Consonantal distinctions
• B. The rhythm of speech
• C. Frequency, intensity, and duration of speech sounds
• D. Speech clarity

Answer: (C)

A spectrogram visually encodes how the frequencies in speech change over time and how strong those frequencies are, including how long they persist. Time runs left to right, frequency is shown up the vertical axis, and the brightness or color intensity reflects the energy (amplitude) at each frequency. This combination reveals the frequency content (like formants and harmonics), the relative intensity of those frequencies, and the duration of sounds. While consonant patterns can be seen in how energy distributes over time, the spectrogram isn’t limited to consonants or to rhythm alone; it presents the full spectral-temporal profile of speech, which is why it’s best described as representing frequency, intensity, and duration.