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PHONE SOUNDS DTMF Dualtone multifrequency signals Phone keypad Digits only Sound effects SFX
>> YOUR LINK HERE: ___ http://youtube.com/watch?v=HaXqLl5sG3w
DTMF SIGNALS • Dual-tone multi-frequency signaling (DTMF) is a telecommunication signaling system using the voice-frequency band over telephone lines between telephone equipment and other communications devices and switching centers. • This particular multi-frequency signaling method uses a mixture of two pure sine tones, each from a different group of frequencies. • • DTMF keypad frequencies (digits only): • 1: 1209+697 • 2: 1336+697 • 3: 1477+697 • 4: 1209+770 • 5: 1336+770 • 6: 1477+770 • 7: 1209+852 • 8: 1336+852 • 9: 1477+852 • 0: 1336+941. • According to ETSI TBR 21, the level of the tone in the high frequency group (1209, 1336, 1477, 1633) shall be 1 dB to 4 dB higher than the level of the tone in the low frequency (697, 770, 852, 941), and both the tone and pause duration should be not less than 65ms. • The Australian tone plan sets the level of the tone in the high frequency group to be 2 dB higher than the level of the tone in the low frequency, and the minimum values of the tone and pause duration to 50ms and 70ms, respectively. • In this example, the level of the tone in the high frequency is 2 dB higher than the level of the tone in the low frequency, the tone duration is 0.1 seconds, and the pause duration 1.0 seconds. • • #phone #call #dtmf #signals #dual #tone #multi #frequency #tones #keypad #digits #sound #effects #sfx
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