The development of capable smartphones and other portable devices has ushered new ways of communication and collaboration. For example, smartphones are widely used for sharing files with friends and colleagues at meeting or a conference. In this case, conventionally, short-range radio, such as Bluetooth or Wi-Fi are used. Encrypted data can be send via Bluetooth radio and be received by any devices in a 10m distance. In public places, this increases the likelihood of security breach and communication eavesdrop as the data may be intercepted by any device within range. In this paper, we propose to improve security by controlling the communication range via acoustic waves. Unlike radio waves, acoustic waves' propagation range can be controlled by modifying their amplitude; thus, it is possible to reduce the data sharing range specifically to a range of a specific device. Our preliminary tests by sharing data between two Nexus 5 smartphones indicate that it is possible to unidirectional control the sharing range while sharply reducing any possibility to eavesdrop on the communication. This increased the communication security since only devices within the specified range and direction were aware of the data sharing.