Call-Progress Tones, by Country
A reference collection of 1,537 authentic phone tones from 193 countries, covering the dial, ringing, busy, congestion and 42 other call-progress tone types defined by national standards.
A phone tone is a tiny piece of cultural shorthand. The dial tone in a French apartment building is at 440 Hz, while in Berlin it is at 425 Hz, and in Manhattan it is a chord of 350 and 440 Hz. The differences are subtle in isolation and instantly recognisable in context: a viewer in Tokyo will know within half a second that the phone they are hearing on screen is not from their country, even if they could not tell you why. Getting these tones right is the kind of detail that nobody compliments and everybody notices when it is wrong. The library documented here is an attempt to make that easy: 1,537 files covering 46 different call-progress tones across 193 countries, organised so that the correct tone for any given scene is one search away.
Each tone is built to its national standard rather than approximated. Where a country uses 425 Hz with a 1.0 s on / 4.0 s off cadence for the ringing tone, the file in the library does the same. Where a country uses two frequencies and a different cadence, that is what is included. The collection ships as 48 kHz / 24 bit WAV files with full UCS 8.2.1 metadata, sold under the SHAPINGWAVES License Agreement for use in film, television, games, radio drama and any other production where authenticity matters.
The tone types covered
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Dial tone
Plays when the user picks up the handset and the exchange is ready to receive call information. Continuous in most countries, with the exception of Italy, which uses an interrupted cadence. North America uses a 350 + 440 Hz dual frequency, ETSI countries use a 425 Hz single frequency, and the UK uses 350 + 450 Hz.
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Ringing tone (ringback)
What the caller hears while the destination phone is being rung. Distinct from the ringtone of the destination phone itself. Cadences vary widely: ETSI countries use 1.0 s on / 4.0 s off, the UK and Ireland use the recognisable double-burst pattern (0.4 s on / 0.2 s off / 0.4 s on / 2.0 s off), and the United States uses 440 + 480 Hz with a 2 s on / 4 s off cadence.
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Busy signal
Indicates that the called line is occupied. Tone families include 425 Hz at 0.5 s on / 0.5 s off (ETSI), 480 + 620 Hz at 0.5 s on / 0.5 s off (North America), 400 Hz at 0.75 s on / 0.75 s off (UK) and 425 Hz at 0.375 s on / 0.375 s off (Australia).
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Congestion or reorder tone (fast busy)
Played when the network cannot complete the call because the lines or switching equipment necessary to set it up are temporarily engaged. Almost universally a faster version of the busy signal: ETSI uses 425 Hz at 0.25 s on / 0.25 s off, twice the rate of the busy tone in the same network. Often called "fast busy" in everyday language.
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Special information tone (SIT)
The distinctive three-tone sweep heard before recorded announcements such as "the number you have dialled is not in service". ETSI and UK networks use 950, 1400 and 1800 Hz played in sequence at 0.33 s each, followed by 1.0 s of silence and the recorded message. North American networks use different frequencies under the ATIS T1.401 standard, with high-variant tones at approximately 985.2, 1428.5 and 1776.5 Hz, and low-variant tones at 913.8, 1370.6 and 1776.5 Hz. Originally designed for automated call-failure equipment, but instantly recognisable to human listeners as well.
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Call waiting (zip tone)
Heard during a call to indicate that another caller is trying to reach the line. ETSI uses 425 Hz with a 0.2 s on / 0.6 s off / 0.2 s on / 3 s off cadence, and the United States and Australia use comparable but distinct patterns.
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Disconnect, confirmation, holding and other supervisory tones
The remaining tones in the collection cover the rest of the supervisory vocabulary: disconnect tone (the far end has hung up), confirmation tone (the exchange has accepted a service request), holding tone, recorder warning tone, stutter dial tone (used as a message-waiting indicator) and the GSM/3GPP "call dropped" tone, plus several other country-specific signals.
"A massive collection of every phone call sound I'll ever need, perfectly categorized."
What a call-progress tone actually is: a short primer
Three parameters: frequency, cadence, duration
Every call-progress tone is defined by three parameters: one or more frequencies (in Hz), an on-off cadence (in seconds) and a total duration. Telecommunication equipment such as fax machines and modems is designed to recognise certain tones automatically, so the tolerances on these parameters are tight: in the United States precise tone plan, no frequency may vary by more than 1.8% from its nominal value, or the switching centre will ignore the signal. The "twist" between the high and low frequencies (the loudness difference between the two components in a dual-frequency tone) can be up to 3 dB.
Why two frequencies in North America, one in Europe
The choice of single-frequency or dual-frequency tones reflects a deliberate engineering compromise. North America's precise tone plan deliberately picked frequency pairs whose harmonics and intermodulation products do not collide with each other: no frequency is a multiple of another, the difference between any two frequencies does not equal any of the frequencies, and the sum of any two does not equal any of the frequencies. The original ratio between the frequencies was 21/19, slightly less than a whole tone in musical terms. ETSI's harmonised European plan instead uses a single 425 Hz tone for almost every supervisory signal, distinguishing them by cadence rather than by frequency, which is simpler to generate but offers less robustness to noise on the line.
Regional standards: a quick comparison
| Tone | North America | ETSI (most of EU) | UK |
|---|---|---|---|
| Dial tone | 350 + 440 Hz, continuous | 425 Hz, continuous | 350 + 450 Hz, continuous |
| Ringing tone | 440 + 480 Hz, 2 s on / 4 s off | 425 Hz, 1 s on / 4 s off | 400 + 450 Hz, 0.4 / 0.2 / 0.4 / 2.0 s |
| Busy signal | 480 + 620 Hz, 0.5 s on / 0.5 s off | 425 Hz, 0.5 s on / 0.5 s off | 400 Hz, 0.75 s on / 0.75 s off |
| Congestion / reorder | same frequencies as busy, 0.25 s on / 0.25 s off | 425 Hz, 0.25 s on / 0.25 s off | 400 Hz, 0.4 / 0.35 / 0.225 / 0.525 s cadence |
| Special info tone (SIT) | ~985 / 1428 / 1776 Hz (or low variant ~913 / 1370 / 1776 Hz), per ATIS T1.401 | 950 / 1400 / 1800 Hz sweep, 0.33 s each | 950 / 1400 / 1800 Hz sweep, 0.33 s each with 0.33 s gaps |
Notable national exceptions to the ETSI plan include France (440 Hz throughout, instead of 425 Hz), Italy (interrupted dial tone instead of continuous), Ireland (UK-style ringback tone) and Australia (its own AS/CA S002 plan with five different dial-tone variants). Networks elsewhere generally follow either ETSI, the North American plan or the UK plan, with regional cadence differences.
From copper to digital, and what survived
The tones originated as analogue signals generated by the central office switch and sent over the copper pair to the calling party. As switching moved to digital and then to voice over IP, the same tones continued to be produced, often by the local switch or even by the telephone itself, generated digitally to the same frequency-and-cadence specifications. Modern signalling protocols such as SS7 carry call status as data rather than as audio, so a ringback heard on a long-distance call may be generated locally by the home network rather than by the destination switch. The tones in this library follow the standardised specifications, which means they correctly represent both the analogue era and the modern digital networks that emulate it.
Why this matters in fiction
Audiences process call-progress tones below the level of conscious attention. A British viewer hearing a US dial tone in a scene set in a London flat will register it as wrong without being able to articulate why; a North American viewer hearing a 425 Hz European busy signal in a scene set in Chicago will do the same. Period drama is even less forgiving: national tone plans have been revised over the decades, and using a contemporary tone in a 1950s scene (or a modern continuous dial tone in a country that historically used an interrupted one) breaks immersion in a way that costumes and set dressing cannot compensate for. The library is organised by country and tone type to make finding the right one for a scene a matter of two filters in a sound-effects browser.
How the material is typically used
In post, this kind of source material falls into a few common buckets. As literal call sounds in dialogue scenes (the moment before someone picks up, the busy signal that triggers a plot beat, the SIT that precedes a "this number is not in service" voicemail). As atmospheric layers in office and call-centre scenes, where a faint ringing tone or congestion tone underneath the dialogue grounds the location. As source material for sound design, where a stutter dial tone or SIT can be pitched, looped or modulated for tech-themed UI design. And as period-correct detail in historical drama, where the right tone for the right country and decade is the difference between a believable scene and one that takes the audience out of it.
- File count
- 1,537 WAV files
- Tone types
- 46 distinct call-progress tone types
- Country coverage
- 193 countries, organised by country and tone type
- Sample rate / depth
- 48 kHz / 24 bit, WAV
- Standards reference
- ITU-T E.180 / E.182, ETSI harmonised guidelines, North American precise tone plan, UK national plan, AS/CA S002 (Australia)
- UCS category
- TELEPHONE (with country and tone-type subcategories)
Cataloguing: UCS and forty languages
Every WAV in the collection follows UCS 8.2.1 naming and carries more than twenty fields of embedded metadata, written into BWAV, iXML, LIST/INFO and Soundminer chunks: CategoryFull, Category, SubCategory, CatID, FXName, Description, BWDescription, CDDescription, CDTitle, Recordist, Designer, Artist, Manufacturer, Publisher, Source, URL, VendorCategory, ixmlNote, OpenTier, LongID, ShortID, Library, Keywords, TrackTitle, Microphone, Location, MicPerspective, RecMedium, RecType, Track, Version, ISRC.
The descriptive fields (Description, BWDescription, CDTitle, TrackTitle, CDDescription, FXName and Keywords) are translated into forty languages, including Arabic, both Chinese variants, French, German, Hindi, Japanese, Korean, Portuguese, Russian, Spanish, Turkish and Vietnamese, and ship as TSV and XLSX sidecars next to the audio.
"A massive collection of every phone call sound I'll ever need, perfectly categorized. Every project I work on films in several different locations around the world and now I can quickly access the correct phone sounds needed for any scene."
George Haddad, Supervising Sound Editor, Formosa Group Burbank"The ShapingWaves collections are full of extremely well recorded, professionally catalogued dynamic sounds. SHAPINGWAVES has assembled unique library material that pushes each one of its categories to the next level, very useful for sound designers everywhere."
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Matt Temple, Sound Supervisor (The Passion of the Christ, The Office)The work documented here lives on as the Phone Call Tones sound library, distributed as a 48 kHz / 24 bit WAV download of 1,537 files with full UCS metadata, under the SHAPINGWAVES License Agreement for use in film, television, games and other media productions.