EP = earpiece
ES = external speaker
WH = wired headset
BTH = Bluetooth headset
HS = handset
SP = speakerphone

gain_table.bin

earpiece call gain sounds coming out of the earpiece when on a call
earpiece inner keypad gain affects sounds coming out of the earpiece when NOT on a call (touchtones, button press beeps)
earpiece system tone gain affects system tones coming out of the earpiece when on or attempting a call (call drop tone, voice dial failed tone, call failed tone, headset disconnect tone)
external speaker speakerphone gain affects sounds coming out of the external speaker when on a call with speakerphone activated
external speaker keypad gain when on speakerphone call affects keypress sounds and system tones coming out of the external speaker when on a call with speakerphone activated
external speaker mp3/midi/video gain affects multimedia, mp3, and midi sounds coming out of the external speaker (includes midi/mp3 tones, video playback)
external speaker system tone gain effects system tones coming out of the external speaker (reminder tone, style/volume change tone, Continental/Siren/Attention/Classic ringtones, low batt tone, service tone, autoredial ring, roaming ringtone)
wired headset call gain affects sounds coming out of the wired headset when on a call
wired headset inner keypad gain affects sounds coming out of the wired headset when NOT on a call (touchtones, button press beeps)
bluetooth headset call gain affects sounds coming out of the bluetooth headset when on a call
bluetooth headset inner keypad gain affects sounds coming out of the bluetooth headset when NOT on a call (touchtones, button press beeps)
external speaker system tone gain when bluetooth headset connected affects ALL SOUNDS coming out of the phone when a bluetooth headset is connected (because only system tones can come out of a motorola phone when a bluetooth headset is connected)
earpiece voice name/voice record playback gain affects sounds coming out of the earpiece during playback of voice records, scrolling through phonebook entries with a voice name, and name confirmation during voice dial
wired headset mp3/midi/video gain affects multimedia, mp3, and midi sounds coming out of a wired headset when connected (includes midi/mp3 tones, video playback)
external speaker voice dial gain when on speakerphone call affects sounds coming out of the external speaker when browsing phonebook entries with voice names
bluetooth voice name/voice record playback gain affects sounds coming out of the bluetooth headset during playback of voice records, scrolling through phonebook entries with a voice name, and name confirmation during voice dial

handset microphone gain affects the sensitivity of the microphone when on a call
wired headset microphone gain affects the sensitivity of the microphone when on a call with a wired headset connected
speakerphone microphone gain affects the sensitivity of the microphone when on a call with speakerphone activated
bluetooth headset microphone gain affects the sensitivity of the microphone when on a call with a bluetooth headset connected

master gain control affects all sounds coming out of all speakers and the sensitivity of all phone microphones