3 ms·

does that apply to ultrasonic toothbrushes too?

knodi123 5y ago
Probably not- the faster sonicare toothbrushes vibrate at 512 Hz, while sonograms are between 2,000,000 to 18,000,000 Hz. There's probably a significant difference in power levels, too.
- sxv 5y ago
  "Ultrasonic" is by definition above 20,000 Hz. According to wiki[0] an ultrasonic toothbrush typically operates on a frequency of 1.6 MHz. [0]https://en.wikipedia.org/wiki/Ultrasonic_toothbrush https://en.wikipedia.org/wiki/Ultrasonic_toothbrush
  - knodi123 5y ago
    When measured, it apparently came out to about 262.5 Hz for Sonicare. https://pubmed.ncbi.nlm.nih.gov/15575438/ https://pubmed.ncbi.nlm.nih.gov/15575438/ And that makes sense. On the face of it, the idea that the bristles are vibrating in the MHz range is just absurd. "Ultrasonic" is by definition above the human range of hearing, which is about 20,000 Hz as you said. I own a sonicare. I've heard it. It's not inaudible. :-)
    - jml7c5 5y ago
      The Sonicare is marketed as a "sonic" toothbrush (a marketing tactic that I never really understood), so it's not too surprising that it's in the audible range. I suspect that you, like myself, assumed parent was writing "ultrasonic" by mistake and didn't look too carefully at the wiki link they posted. But to my surprise, true ultrasonic toothbrushes are real! Take a look at the link; apparently they typically operate at 1.6 MHz.
- schoen 5y ago
  Wow, I had no idea that we even had the technology to produce sounds at that kind of frequency, let alone that it was routinely used!
  - williamscales 5y ago
    The piezoelectric effect is used to do this[0]. This other wiki page[1] has some neat pictures of what the sound field looks like. [0] https://en.wikipedia.org/wiki/Ultrasonic_transducer https://en.wikipedia.org/wiki/Ultrasonic_transducer [1] https://en.wikipedia.org/wiki/Ultrasonic_transducer#Transducers https://en.wikipedia.org/wiki/Ultrasonic_transducer#Transduc...

Probably not- the faster sonicare toothbrushes vibrate at 512 Hz, while sonograms are between 2,000,000 to 18,000,000 Hz. There's probably a significant difference in power levels, too.

sxv 5y ago
"Ultrasonic" is by definition above 20,000 Hz. According to wiki[0] an ultrasonic toothbrush typically operates on a frequency of 1.6 MHz. [0]https://en.wikipedia.org/wiki/Ultrasonic_toothbrush https://en.wikipedia.org/wiki/Ultrasonic_toothbrush
- knodi123 5y ago
  When measured, it apparently came out to about 262.5 Hz for Sonicare. https://pubmed.ncbi.nlm.nih.gov/15575438/ https://pubmed.ncbi.nlm.nih.gov/15575438/ And that makes sense. On the face of it, the idea that the bristles are vibrating in the MHz range is just absurd. "Ultrasonic" is by definition above the human range of hearing, which is about 20,000 Hz as you said. I own a sonicare. I've heard it. It's not inaudible. :-)
  - jml7c5 5y ago
    The Sonicare is marketed as a "sonic" toothbrush (a marketing tactic that I never really understood), so it's not too surprising that it's in the audible range. I suspect that you, like myself, assumed parent was writing "ultrasonic" by mistake and didn't look too carefully at the wiki link they posted. But to my surprise, true ultrasonic toothbrushes are real! Take a look at the link; apparently they typically operate at 1.6 MHz.
schoen 5y ago
Wow, I had no idea that we even had the technology to produce sounds at that kind of frequency, let alone that it was routinely used!
- williamscales 5y ago
  The piezoelectric effect is used to do this[0]. This other wiki page[1] has some neat pictures of what the sound field looks like. [0] https://en.wikipedia.org/wiki/Ultrasonic_transducer https://en.wikipedia.org/wiki/Ultrasonic_transducer [1] https://en.wikipedia.org/wiki/Ultrasonic_transducer#Transducers https://en.wikipedia.org/wiki/Ultrasonic_transducer#Transduc...