Not all decks have custom sounds, but nearly every deck will play "ting" or "whoops" sound effects.
If you are not hearing any sounds, first make sure you did not mute the player. There should be one of these icons in the top left corner of the player:
The first means all sounds are on, the second turns off feedback sounds, the third turns off all sounds. Tap or click the icon to change between them. If the player is not muted, check the following:
1. Is your device muted, or is its volume turned down?
2. Is your device using a mode that mutes sounds and notifications, such as Silent Mode, Do Not Disturb, Total Silence or a similar setting?
3. If you are using an iDevice, is your sound hijacked by a nearby Bluetooth device? You can check this by disabling Bluetooth. More information about sound on iDevices can be found here.
4. If you added the sound files yourself, is the sound file in a format other than MP3? Information about converting files to MP3 can be found here.