Bug Vanquisher

14 April 2007

A facility turning a foul: Day 2

Filed under: Decontamination — Tanveer Badar @ 8:18 PM

Yesterday, I wrote about how a stupid message is causing chain SMS in even stupider customers. Now, it seems people are coming up with all sorts of funny explanations which lack the elegance of educated nature.

I received a SMS telling me that the sender heard it from his close friend that he talked to two eye witnesses of that phone call death. Quite a short chain of trust, don’t you think? Only four hops to the victim! Would you believe that I heard from my second cousin’s uncle who heard it from his friend that he worked with an eye witness who saw aliens landing in Mexico? It’s the same sort of junk. When I pointed it to him, his story changed and he said he heard it from top RF and Telecom engineers.

Human ears are only capable of hearing from frequencies 20 Hz up to 20-22 kHz. Exact values are different for individuals but these ranges have the most consensus. Infrasonic can only be felt but don’t have enough energy to cause any damage. Ultrasonic bounce off various body structures very badly, not imparting much energy during the process. In terms of power (or loudness) we can endure up to 90 dB easily and sounds between 90 dB and 120 dB damage hairs inside inner ear and about 120 dB, all bets are off. No mobile phone can emit even 90 dB during a call which is the level of noise when a jet engine passes overhead. I am not talking about souped up MP3 players which happen to include cellular functionality just by incident. Land lines clip the frequency of captured voice to 4 kHz, the reason your modem cannot go about 64 Kbps. Cell phone have even worst reception and transmission. Note that it is the carrier that is limiting the frequency not the device, this filtering happens in telephone exchanges over which you have no control. Even if you heard 90 dB from a source over which you had total control, you would shut it in a matter of seconds. It annoys that much! Below that level, there is no permanent damage. Therefore, I reject the theory of some voice causing damage.

Turning to the other agent the mobile carrier. I don’t have precise data about the frequency ranges used in transmission and receiving, but it isn’t enough to cause damage to anything in such a short time period. It is claimed that the caller is bypassing all these filters, but cell phones also have embedded decoders and prefilters which reject everything above a cutoff frequency in the range 4 kHz to 8 kHz. There is no way such an ultra hi-fi (pun intended) frequency could damage neurons or hair cells inside ears. These days, we work in an environment immersed in wireless traffic. Talk about cell phones, garage door openers, TV remote controls, cordless phones, IR file transfer among mobile devices, blue tooth, wireless USB, wireless LANs, IR connected devices, WI-Fi, microwaves, radios, satellite communication, microwave background, RFID chips, speed guns for traffic police, advanced burglar alarms and many more. If cell phones are danger to human health some of these things have a much higher potential for causing death than cell phones. If you are so much concerned about it, use a closed user group, a white list for outgoing calls and another white list for incoming calls.

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