For the sound level of the handset, if this is not loud enough, press J: , the audio boost wiki be activated (+10dB). To turn off audio hoots, press again the key 2. 5. PRIVATE PHONE BOOK Your phone can store up to 100 private phone book entries with names and numbers. Each phone book entry can have a maximum of 24 digits for the phone number and 12 characters for the name. You can also select different ringtones for your phrasebook entries. Phone book entries are stored alphabetically by name. 5.1.