| ??? 06/21/06 08:09 Read: times |
#118705 - Don't do that! Responding to: ???'s previous message |
Hal Albach said:
Would it be feasable to have a higher pitched device fill the room with, say, 19-20 kHz sound that no one can hear. That is a very bad idea: I'm sure there are plenty of people (especially the young ones) who could hear that, or at least sufficiently "sense" it to be annoying or even harmful. And think of the effect on all the dogs in the area... However, it would be easy enough to build a detector that would give some indication of the presence of any signal over a certain frequency - just a microphone and high-pass filter, really! But what's the point? If the high-pitched ringtones are detected, the students will just switch their phones to vibrate (silent) instead... :-( |
| Topic | Author | Date |
| High pitched ring tones | 01/01/70 00:00 | |
| LM556 | 01/01/70 00:00 | |
| Download The Ring Tone. | 01/01/70 00:00 | |
| Adding signals with two frequencies | 01/01/70 00:00 | |
| Sure? | 01/01/70 00:00 | |
| Yes, quite sure. | 01/01/70 00:00 | |
| Intermodulation not beat frequencies | 01/01/70 00:00 | |
| Remember piano tuners | 01/01/70 00:00 | |
| A test should tell it | 01/01/70 00:00 | |
| Tuning instruments. | 01/01/70 00:00 | |
| Yes, but... | 01/01/70 00:00 | |
| Mixing 2 ultrasonic frequencys | 01/01/70 00:00 | |
| Cool! | 01/01/70 00:00 | |
| We experimented with the "ionovac" | 01/01/70 00:00 | |
Mixing two rf signals | 01/01/70 00:00 | |
| Adding signals with two frequencies | 01/01/70 00:00 | |
| Don't do that! | 01/01/70 00:00 | |
| I'm with Andy | 01/01/70 00:00 | |
| active noise reduction | 01/01/70 00:00 | |
| Rest your fears | 01/01/70 00:00 | |
| a better idea | 01/01/70 00:00 | |
| Detecting high pitch sounds | 01/01/70 00:00 | |
| No, no, do it the hard way | 01/01/70 00:00 |