Checking wifi signal interference could be done in order to minimize its effect.
There are a tremendous number of 802.11 devices out there. It is true that the other 802.11 networks can cause interference with your network. This type of interference is known as co-channel and adjacent channel interference. But since other 802.11 devices follow the same protocol, they tend to work cooperatively-that is, two access points on the same channel will share the channel capacity.
To optimize your wifi operation, we can adjust the channel option in our wifi adapter.
To check the available channel used by other wifi adapter we can use inSSIDer. It will show us wifi condition near our laptop. the visualization is like this
It can also do :
1. Measure Wi-Fi Signal Strength
2. Inform you about wifi channel available
3. Inform you about wifi security used by wifi adapters around you