It can be handheld or positioned on a visor or some central area of the car. Both systems are portable and have use applications outside of the vehicle when traveling or for other day to day activities. For example, the FM transmitter can be given to tour guides, field trip leaders, lecturers or used at meetings or movies. Either system can be used at home for TV listening or general conversation. For those with cellular car phones, there are some products to aid in their use.
Some people have difficulty knowing when the phone rings.
It can sense calls within one to three feet of the phone, depending on the phone's power. The downside is if there is a lot of nearby cellular traffic, false triggering might occur. Amplification for cellular phones is difficult as well. Some phones have volume controls, but even full volume usually isn't loud enough for someone with a hearing loss. Then the volume of the hearing aid can be adjusted for best understanding.