Abbott ICDs (formerly St Jude Medical) have traditionally alerted you by vibration rather than sound. A typical pattern is a six-second vibration, then sixteen seconds of silence, then a further six-second vibration, then ten seconds of silence, after which the pattern repeats.
Historically, many Abbott devices had no patient alert at all. The newer Gallant models have added an audible alert facility, so a Gallant device may beep as well as vibrate.
If you feel an unexpected vibration from your device, contact your ICD clinic, and ask for a demonstration at your next appointment. Our ICD sounds and alerts page explains the alerts by manufacturer.