1. A computer implemented method comprising: accessing a first neural network that was trained to recognize a given keyword or keyphrase using a set of hotword training data, wherein the hotword training data includes positive hotword training data that correspond to utterances of the keyword or keyphrase, and negative hotword training data that corresponds to utterances of words or phrases that are other than the keyword or keyphrase; selecting an audible computer-generated seed hotsound; mapping, to a feature space, (i) the positive hotword training data, (ii) the negative hotword training data, and (iii) the audible computer-generated seed hotsound; performing an optimization of a position of the audible computer-generated seed hotsound within the feature space to generate a modified audible computer-generated hotsound; generating a set of hotsound training data using the modified audible computer-generated hotsound; training a second neural network to recognize the modified audible computer-generated hotsound using the generated set of hotsound training data; using the trained second neural network to recognize the modified audible computer-generated hotsound; and in response to recognizing the modified audible computer-generated hotsound, triggering an action on a device.