The 5th limb in Patanjali's 8 limbs of yoga is Pratyahara - sense withdrawal.
Pratyahara can be translated as withdrawal of the senses. Prati meaning to withdraw and Ahara meaning take in or food. In the instance of Pratyahara, it can defined as withdrawing our mind from outside stimuli. During the practice of pratyahara we learn to disengage from any outside disturbances. The first four limbs of yoga, Yamas, Niyamas, Asana and Pranayama concentrate on the outward aspect of our practice teaching us our moral values, personal observances, breath control ,movement and seated posture. The 6th, 7th and 8th limbs, Dharana, Dhyana and Samadhi concentrate on the inward aspect of our yoga practice, meditation and higher consciousness. Pratyahara can be seen as the link between inner and outer. It is the foundation for our meditation practice.
During meditation, we are often surrounded by outside noises which are beyond our control. It can be hard for us to tune out these noises. During pratyahara we learn to control our reactions to any outside disturbances that may occur. We are able to acknowledge these disturbances but the more we practice pratyahara, the deeper our connection with our internal self becomes, and we are able to not allow these disturbances to disrupt our peaceful state of mind. The more skilled we can become with this the more we are able to carry pratyahara over into our daily lives outside of our yoga and meditation practice. We are able to consciously acknowledge a situation or occurrence and calmly choose our reaction as opposed to reacting. This is not always easy to do, as human nature we tend to 'react', but through practice and a deeper awareness of ourselves we can learn to observe the situation and our thoughts almost from a 3rd person view and then calmly choose our words.
Quieten down your mind, find stillness and observe.