One phase is a continuous call that can last for several minutes; during this period the frequency varies between 5.5–6.2 kHz and 6.0–7.5 kHz 4–6 times a second.
Pada suatu fase panggilan terus-menerus dapat berlangsung selama beberapa menit; selama periode ini frekuensi bervariasi antara 5,5-6,2 kHz dan 6,0-7,5 kHz 4-6 kali per detik.