Choose your time and leave the rest to the bell. A soft chime at the start, at the intervals you choose and at the end; no guide, no music, just you and the silence.
Guided meditations are lovely to begin with; after a while many people want to sit on their own, with nothing but a start and an end signal. That is what the silent session is for: you choose the duration, an optional preparation time and interval bells; the bells ring on time and you stay with your practice without checking the clock. Interval bells act as a gentle reminder when your attention wanders.
A silent session works for any practice where you already have your own method: mindfulness, zazen, contemplation, prayer or simply sitting quietly. Interval bells help especially in long sessions or on days when the mind is very scattered. Even a five-minute sit at lunchtime can change the pace of your day.
Opening and closing a session with a bell or bowl is common to many traditions, from Buddhist monasteries to the Sufi practice of retreat (khalwa). Today one of the most used tools in meditation apps is a simple bell timer. Research suggests regular meditation has moderate benefits for anxiety, depressive symptoms and perceived stress (Goyal et al., JAMA Internal Medicine, 2014, 47 trials). A timer is a tool that makes that regularity easier.
Meditation is generally safe. If you have a history of severe trauma, depression or psychosis, however, long silent sessions can bring up difficult feelings; keep sessions short, feel free to keep your eyes open, and work with a professional if needed. Set the bell to a volume that won't startle you.