State the approximate range of frequencies audible to humans as 20 Hz to 20000 Hz
3.4 Sound
Objective
State the approximate range of frequencies audible to humans: $20 \text{ Hz} \le f \le 20000 \text{ Hz}$ 🎧
Key Concepts
- Sound travels as a longitudinal wave through a medium.
- Frequency ($f$) determines pitch – higher $f$ = higher pitch.
- Human hearing range is roughly 20 Hz (deep bass) to 20 kHz (high whistle).
- As we age, the upper limit often drops to ~16 kHz.
Analogy & Example
Imagine a drum: a deep thump at about 50 Hz feels like a gentle “thump‑thump.” Now think of a whistle or a high‑pitched bird call – those are around 10 kHz, almost like a tiny, rapid “screech.” The human ear can pick up both extremes, but the middle range (200–2000 Hz) is where most speech and music live.
Common Sound Frequencies
| Sound | Typical Frequency Range (Hz) |
|---|---|
| Bass Guitar | 40–200 |
| Human Voice (average) | 85–255 |
| Piano (Middle C) | 261.6 |
| Whistle / Bird Call | 2000–20000 |
Exam Tips
Remember: The audible frequency range is $20 \text{ Hz} \text{ to } 20000 \text{ Hz}$.
• 20 Hz is like a deep drum beat.
• 20 kHz is like a high whistle or a bird chirp.
• In exam questions, if a frequency is <20 Hz or >20 kHz, it’s inaudible to most people.
• Use the word “audible” when describing this range.
Revision
Log in to practice.