# Simulating a telephone in sonic Pi

I thought it would be fun to try to recreate the sound of phone line, including dial tone, DTMF frequencies and ringing. Here’s a recording of what I managed: https://soundcloud.com/emlyn-corrin/touchtone, I think it sounds quite good.

This is the code:

``````# https://en.wikipedia.org/wiki/Dial_tone
# https://help.genesys.com/cic/mergedprojects/wh_ia/desktop/dial_tone,_busy_and_ringback_signals_by_country.htm
DIAL_TONES = {
:uk => [350, 450],
:us => [350, 440],
:eu => [425],
:jp => [400]
}

# http://dialabc.com/sound/dtmf.html
DTMF_TONES = {
'1' => [697, 1209],
'2' => [697, 1336],
'3' => [697, 1477],
'4' => [770, 1209],
'5' => [770, 1336],
'6' => [770, 1477],
'7' => [852, 1209],
'8' => [852, 1336],
'9' => [852, 1477],
'*' => [941, 1209],
'0' => [941, 1336],
'#' => [941, 1477],
'A' => [697, 1477],
'B' => [770, 1477],
'C' => [852, 1477],
'D' => [941, 1477],
}

# also
# http://www.telephonesuk.co.uk/sounds.htm

define :pulses do |freqs, periods|
on = true
periods.each do |t|
if on
freqs.each do |freq|
synth :sine, note: hz_to_midi(freq), sustain: t, release: 0
end
end
sleep t
on = not(on)
end
end

define :dialtone do |tone=:uk, periods=[2]|
tone = DIAL_TONES[tone]
pulses(tone, periods)
end

define :dtmf do |digit, length=0.15, pause=0.15|
tone = DTMF_TONES[digit.to_s.upcase]
pulses(tone, [length, pause]) if tone
end

define :ringring do |rings=1|
pulses([400, 450], [0.4, 0.2, 0.4, 2] * rings)
end

define :phone do |number|
with_fx :distortion, distort: 0.3, mix: 0.3 do
noise = synth :pnoise, amp: 0.03, sustain: 15
dialtone(:uk)
number.split('').each do |n|
dtmf(n)
end
sleep 1
ringring(3)
#control noise, amp: 0
end
end

phone '01632 867 5309'
``````
3 Likes

I’m tempted to try it with this one:

1 Like
2 Likes

HI there,

really funny and the voice told me something… Hey of course it’s Neil Hannon from the Divine Comedy !
Cheers