1. A device, comprising: a processor; and a memory storing instructions that, when executed by the processor, cause the processor to perform operations including: analyzing a plurality of segments of an audio signal based on a lexical evaluation and an acoustic evaluation; determining, for each segment of the plurality of segments, an emotional state from among a plurality of emotional states and a confidence score of the emotional state based on the analyzing of the plurality of segments; tracking a current emotional state of the audio signal for each of the plurality of segments; and determining, for a particular segment of the plurality of segments, whether the current emotional state of the audio signal changes to an other emotional state of the plurality of emotional states based on the emotional state of the particular segment and a comparison of the confidence score of the particular segment to a predetermined threshold.
6. The device according to claim 1 , further comprising: a database that stores the audio signal and tracked emotional states in association with a customer service agent.