Stuka raid on my telephone.

November 19, 2007 6:59 PM

Why does my phone, instead of a dial tone, make a descending sirenesque sound when I pick it up?

When I turn my (landline) phone on, I am greeted with the sound of a Stuka diving over my house. What gives?

The sound starts at a high frequency, falls to a low frequency and disappears. When it disappears, there is no dial tone.

I have a cordless digital phone and an old non-digital phone. The sound occurs on both of them. So the problem is with the phone line itself?

If someone calls me, when I answer, the siren noise sounds, but when it is over I can talk to the caller. I cannot, however, make calls.

That's about the size of it. Please help--naturally, I can't find my cell phone right now either, so I am unable to communicate with the outside world.

posted by Darth Fedor to technology (6 comments total)

Sounds like a test tone has been applied to your line at the phone company's end. You may want to call them to ask what's going on.
posted by autojack at 7:03 PM on November 19, 2007

That's the sound the phone company sends you if you leave your phone off the hook. It's a lot louder than normal, because it's supposed to be audible from six or eight feet away from the handset. That's because they want you to hang the phone up. When it's off hook, it's consuming resources in the switch.

My guess is that there's something wrong with your cordless phone, and it isn't actually hanging up the way it's supposed to.
posted by Steven C. Den Beste at 7:24 PM on November 19, 2007

Autojack has it. It's a sweep tone, which lets a lineman look at the frequency response of the line. The hang-up-the-phone noise (the "howler") should be constant. It will, however, disappear after a long period of time (I'm not sure how long, at least several minutes). You should call the phone company and let them look into it. I'd almost guarantee that some flag was just accidently set wrong on your line.

(And interesting that autojack appears on the phone question. That's a name I haven't seen for a while.)

-kiltedtaco, aka hoho.
posted by kiltedtaco at 7:36 PM on November 19, 2007

If it's not screamingly loud I doubt it's a test or trace tone - which are deliberately very loud, and more of a sweeping high/low warbling; high-low in < a second.

If the volume is about the same or less than normal ~ soft speech, starting off high pitch and falling away to low pitch inaudibility over 4~5 seconds, I'd bet money that it's due to a high-resistance fault in the line. What you're hearing is the effect of the solid-state amplifiers in either the phone or the line cct being starved of power and oscillating on the way down. The reason it comes good when you answer an incoming call is twofold - the ring voltage breaks down the HR fault to some extent, and once answered, the loop current rises as the cap tries to charge. This eventually breaks down the HR joint enough (their behaviour is like a hugely non-linear resistor) that power and therefore speech will get through.

(Used to see this a lot here in Qld about a week after rain - water gets in to a joint, a connection corrodes, but is still fairly low resistance while it's wet. As it dries out over a few days, the resistance rises and eventually causes this fault.)
posted by Pinback at 8:24 PM on November 19, 2007

Pinback's explanation seems reasonable to me.

If you're in the US (and possibly other places), there'll be a demarcation point on the outside of your house, a box where the phone company's line comes in and connects to your house's wiring. Plug a phone into the demarc (there's a plug and jack in there) and see if you have the same symptoms. If so, it's the phone company's problem; call them.
posted by hattifattener at 11:12 PM on November 19, 2007

I have heard this on my phone when we had troubles with the line, which went from being intermittent to being constant. You'd pick up the phone and it would go BEEEOOOOWW very loudly, then nothing. Same symptoms exactly as Darth Fedors description. The only thing that got it working was getting a tech guy out from the phone company to fix it at an exchange some distance away.
posted by tomble at 4:09 PM on November 20, 2007