What Is the EAS Alarm Sound?
The EAS alarm is the attention signal of the US Emergency Alert System — the national warning system that lets officials interrupt radio, TV, cable and satellite programming. The signal is two pure tones, 853 Hz and 960 Hz, played simultaneously. Because the two pitches are close together they clash, producing a rough, pulsing, dissonant drone that is very hard to tune out. That is exactly the point: it tells everyone listening that what follows is an emergency message.
Tones
853 Hz + 960 Hz sine waves mixed together. The 107 Hz difference between them creates the harsh, beating quality.
Duration
The attention signal runs for 8 to 25 seconds on broadcast EAS alerts, right after the data header.
Weather Radio
NOAA Weather Radio uses a different single tone: 1050 Hz, which switches alert-capable radios on.
Anatomy of an EAS Alert
A complete broadcast EAS message has four parts. The simulator plays the attention signal, the part everybody remembers:
- 1. SAME header (“the screech”): three short bursts of digital data, sent with audio frequency-shift keying at about 520 bits per second (tones of 2083.3 Hz and 1562.5 Hz). It encodes who sent the alert, the event type (e.g.
TOR for a tornado warning), the affected counties and the duration. Receivers decode it automatically.
- 2. Attention signal: the 853 + 960 Hz two-tone alarm for 8–25 seconds (or the 1050 Hz tone on NOAA Weather Radio).
- 3. Audio message: the spoken (often computer-voiced) description of the emergency and what to do.
- 4. End of message: three short data bursts that tell equipment the alert is over.
Phones use a related but separate system, Wireless Emergency Alerts, which plays the same two tones in a distinctive long-short-short rhythm together with a special vibration. Hear it on the Amber alert sound page.
Why You Can't Use the EAS Tone in Videos or Broadcasts
Because the attention signal and SAME data can trigger automatic equipment and cause real alarm, the FCC prohibits broadcasters and cable, satellite and other EAS participants from transmitting the EAS codes, the attention signal, or a recording or simulation of them, except during genuine alerts, authorized tests and certain approved public service announcements. The rule has teeth: in 2014 the FCC reached about $1.9 million in settlements with several TV networks that aired a movie trailer containing EAS tones, and it has fined other stations and programmers since.
Online platforms are not covered by that FCC rule, but videos using the tone are routinely flagged, age-restricted or demonetized, and a convincing fake alert can frighten people. That is why this page has no download button: listen and learn, but don't redistribute it.
From CONELRAD to EAS: A Short History
- 1951 – CONELRAD: the first US national warning system. In an attack, stations would leave the air and a few would rebroadcast on 640 or 1240 kHz AM so bombers couldn't navigate by radio signals.
- 1963 – Emergency Broadcast System (EBS): replaced CONELRAD. In the 1970s EBS adopted the two-tone 853 + 960 Hz attention signal, along with the famous “This is a test of the Emergency Broadcast System” announcements.
- 1997 – Emergency Alert System: EAS replaced EBS, keeping the two-tone attention signal but adding the SAME digital header so alerts could be relayed automatically and targeted by area.
- 2012 – Wireless Emergency Alerts: alerts began reaching mobile phones directly, including AMBER Alerts and national alerts.
EAS Alarm FAQ
What is the EAS alarm sound?
Two tones, 853 Hz and 960 Hz, played together for 8–25 seconds after a burst of digital data. Press Play above to hear the tones.
Why is the EAS alarm so scary?
The two pitches are dissonant and beat against each other, the sound interrupts whatever you were watching, and most people only hear it when something serious is happening. Many people describe a genuine fear response to it.
What's the difference between the EAS tone and the NOAA tone?
Broadcast EAS uses the 853 + 960 Hz two-tone signal; NOAA Weather Radio uses a single 1050 Hz tone. Both follow a SAME data header.
Can I download the EAS alarm?
Not from this page. Downloads are disabled here because redistributing the tone can violate FCC rules or platform policies and can be mistaken for a real alert.
Is this a real emergency alert?
No. Nothing on this page is connected to any alerting system. For real alerts, rely on your phone's Wireless Emergency Alerts, NOAA Weather Radio and local broadcasts.
More Warning Sounds You Can Play