A mobile device locator configured to be included in a mobile device, the mobile device locator comprising: a correlator configured to: receive first and second acoustic signals detected by a microphone of the mobile device and respectively transmitted via first and second speakers located in a vehicle cabin, the first and second acoustic signals comprising a first acoustic detection pattern and a second acoustic detection pattern; compare the detected first and second acoustic signals with respective predetermined first and second detection patterns (126,128); and to output a respective first matched acoustic signal and a second matched acoustic signal, wherein the first detection pattern and the second detection pattern are mutually orthogonal; and to detect a check detection pattern included in a check acoustic signal transmitted by the mobile device; a time difference of arrival module coupled to the correlator output and configured to determine a time difference of arrival between the first matched acoustic signal and the second matched acoustic signal; a received signal strength indicator coupled to the correlator wherein the received signal strength indicator is configured to determine a received signal strength of the first and second acoustic detection patterns from the first matched acoustic signal and the second matched acoustic signal; and a location region indicator coupled to the time difference of arrival module and the received signal strength indicator and configured to determine a location of the mobile device within a region of the vehicle cabin based on the determined received signal strength and time difference of arrival and to output a mobile device operating mode signal dependent on the determined mobile device location; and the received signal strength indicator is further configured to determine a received signal strength of the check detection pattern; and the location region indicator is further configured to indicate a fault in response to the received signal strength of the check detection pattern being below a predetermined threshold value, thereby protecting against tampering the mobile phone by blocking the microphone. receive first and second acoustic signals detected by a microphone of the mobile device and respectively transmitted via first and second speakers located in a vehicle cabin, the first and second acoustic signals comprising a first acoustic detection pattern and a second acoustic detection pattern; compare the detected first and second acoustic signals with respective predetermined first and second detection patterns (126,128); and to output a respective first matched acoustic signal and a second matched acoustic signal, wherein the first detection pattern and the second detection pattern are mutually orthogonal; and to detect a check detection pattern included in a check acoustic signal transmitted by the mobile device; a time difference of arrival module coupled to the correlator output and configured to determine a time difference of arrival between the first matched acoustic signal and the second matched acoustic signal; a received signal strength indicator coupled to the correlator wherein the received signal strength indicator is configured to determine a received signal strength of the first and second acoustic detection patterns from the first matched acoustic signal and the second matched acoustic signal; and a location region indicator coupled to the time difference of arrival module and the received signal strength indicator and configured to determine a location of the mobile device within a region of the vehicle cabin based on the determined received signal strength and time difference of arrival and to output a mobile device operating mode signal dependent on the determined mobile device location; and the received signal strength indicator is further configured to determine a received signal strength of the check detection pattern; and the location region indicator is further configured to indicate a fault in response to the received signal strength of the check detection pattern being below a predetermined threshold value, thereby protecting against tampering the mobile phone by blocking the microphone.