Valentines Day in South Korea means chocolates, romantic dinners and a high-tech mobile phone device that can secretly check the passion in the voice of a lover.

The “Love Detector” service from mobile operator KTF uses technology that is supposed to analyze voice patterns to see if a lover is speaking honestly and with affection. “We created this service because we thought people would want to know what others were feeling about them”, said Ahn Hee-jung, a KTF official.

Users who speak by pointing their mobile phones at themselves for video conferences can see a “love meter” bar on the screen of their handset during a conversation. They later receive an analysis of the conversation delivered through text message that breaks down the amount of affection, surprise, concentration and honesty of the other speaker.