How to use the Tone Generator
- Lower the system volume first and choose a waveform and output channel.
- Drag the frequency slider or type a frequency in Hz, or choose a note such as A4 = 440 Hz.
- Press Play; use sweep mode to set start and end frequencies and duration.
- Press Stop when done. Long, loud or high-pitched tones can harm hearing.
Frequencies and note names
The standard pitch A4 is 440 Hz, and each octave doubles the frequency (A5 = 880 Hz). In equal temperament adjacent semitones differ by a factor of 2 to the power 1/12. The tool shows the nearest note and the offset in cents for tuning reference.
The four waveforms
A sine wave has a single frequency and is best for hearing and speaker tests. A square wave adds odd harmonics and sounds harsh. A sawtooth contains all harmonics and is common in synthesizers. A triangle has fewer harmonics and sounds softer than a square. Use sine waves for device testing.
Useful test frequencies
50/60 Hz: mains hum troubleshooting. Below 100 Hz: subwoofers and room modes. 1 kHz: the standard audio reference. Above 10 kHz: treble and hearing range. Human hearing spans about 20 Hz to 20 kHz, with the upper limit dropping with age.
Frequently asked questions
What is the highest frequency?
It is limited to about half the audio sample rate (about 24 kHz at 48 kHz). The tool caps at 22 kHz; many speakers struggle above 18 kHz anyway.
Why can I not hear low frequencies?
Laptop and phone speakers usually cannot reproduce frequencies below about 100 Hz. Use headphones or a subwoofer.
Can I tune an instrument with it?
Yes, as a reference pitch such as A4 at 440 Hz. A dedicated tuner is better for precise tuning.
Why do I hear a click?
The tool fades in and out to avoid clicks. Remaining clicks usually come from Bluetooth switching or very high system volume.
Do high-frequency tones repel mosquitoes?
There is no reliable evidence for that, and the tool does not offer it. Long high-pitched playback can also bother children and pets.