--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pirelli/audio-tones	Wed Nov 10 01:22:36 2021 +0000
@@ -0,0 +1,37 @@
+Keybeep in handheld mode:
+
+KBP_R fn da3b da3b 0004
+
+The two overlapping da3b tones (697 Hz, -7 dBfs) are exactly the same
+as in TCS211 reference.
+
+This 2x da3b keybeep remains the same in an active call, and also when the
+loudspeaker is enabled.  With the loudspeaker on, the beeps are very loud!
+
+With the headset plugged in, the keybeep changes to:
+
+KBP_R fn da0b da0b 0004
+
+This headset mode keybeep still consists of two overlapping 697 Hz tones,
+but now the amplitude of each single tone is -21 dBfs.
+
+Keybeep duration is 120 ms in TCS211 reference, but only 80 ms in Pirelli's
+version.
+
+Switching to DTMF keypad mode:
+
+All keys beyond the basic dial set generate the same tone as the # key:
+
+TON_R fn bd4c 6683 0000 0001 000a 000a 0005 0000 0005 0000 0005 0000 0005
+
+The above trace was captured in handheld mode.  The frequencies are the same
+as in TCS211 reference (941 Hz low, 1477 Hz high), and the dBfs amplitudes are
+also unchanged: -7 dBfs for the low tone, -5 dBfs for the high tone.
+
+With the headset plugged in, the tone changes to:
+
+TON_R fn bd0f 661a 0000 0001 000a 000a 0005 0000 0005 0000 0005 0000 0005
+
+The new amplitudes are -21 dBfs for the low tone and -19 dBfs for the high tone.
+
+The duration of the tone is 100 ms, same as in TCS211 reference.