Didier Stevens

Tuesday 13 June 2006

A Ring Tone That I Cannot Hear

Filed under: technology — Didier Stevens @ 17:10

Teenagers have a new ring tone that adults cannot hear, because the frequency is too high: 17 kHz.

Test it with Audacity:

File / New

Generate / Tone… Frequency: 17000

Play it.

I cannot hear it. But I can hear a 14 kHz tone.

The ring tones are appearing on the net: here and here.

Analyzing the first one with Audacity (Analyze / Plot Spectrum) reveals a peak at 15 kHz.

Keep this in mind when testing:

  1. your hardware (sound card, speakers, …) must be able to handle the frequency (20 kHz is a common limit)
  2. when exporting as mp3, select the right sampling frequencies (Nyquist)

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