An apparatus for determining a reliability of a recommendation based on an environment of a vehicle may include: an input device configured to detect a sound in the vehicle; a storage configured to store information associated with the sound; an output device configured to output information associated with a recommendation action; and a controller electrically connected with the input device, the storage, and the output device. The controller can be configured to: obtain audio information using the input device; obtain acoustic state information of the vehicle based on the audio information and a state of the vehicle, the acoustic state information associated with the state of the vehicle and noise included in the audio information; determine context information of the vehicle when the audio information is obtained; perform speech recognition on the audio information to obtain text information; calculate a recommendation index for one or more actions corresponding to the text information and the context information; and generate a recommendation of at least one of the one or more actions based on the acoustic state information and the calculated recommendation index.