P u s h t o t a l k66Select Menu > Media > Equaliser.To activate a set, scroll to one of the equalizer sets, and select Activate.To view, edit, or rename a selected set, select Options > View, Edit, orRename. Not all sets can be edited or renamed.■ Stereo wideningStereo widening enhances the audio output of stereo enhancements byenabling a wider stereo sound effect. To change the setting, selectMenu > Media > Stereo widening.13. Push to talkIf available, select Menu > Push to talk.Push to talk (PTT) over cellular is a two-way radio service available overa GPRS cellular network (network service).You can use PTT to have a conversation with one person or with a groupof people (channel) having compatible devices. While you are connectedto the PTT service, you can use the other functions of the phone.To check availability and costs, and to subscribe to the service, contactyour network operator. Roaming services may be more limited than fornormal calls.Before you can use the PTT service, you must define the required PTTservice settings. See “PTT settings,” p. 71 and “Configuration settings,”p. 72.■ PTT channelsA PTT channel comprises a group of people (for example, friends or aworkteam) who joined the channel after they where invited to. Whenyou call a channel, all members joined to the channel hear the callsimultaneously.There are different types of PTT channels: