1. A method comprising: selecting, by a computing device, a first gender-specific speaker adaptation technique based on characteristics of a first set of feature vectors, wherein the first set of feature vectors correspond to a first unit of input speech, and wherein the first set of feature vectors are configured for use in automatic speech recognition (ASR) of the first unit of input speech, wherein the first gender-specific speaker adaptation technique is associated with a particular gender; modifying a second set of feature vectors based on the first gender-specific speaker adaptation technique, wherein the second set of feature vectors correspond to a second unit of input speech, and wherein the modified second set of feature vectors are configured for use in ASR of the second unit of input speech; based on characteristics of the second set of feature vectors and the first gender-specific speaker adaptation technique being associated with a particular gender, selecting a first speaker-dependent speaker adaptation technique that is associated with a particular speaker of the particular gender; and modifying a third set of feature vectors based on the first speaker-dependent speaker adaptation technique, wherein the third set of feature vectors correspond to a third unit of input speech, and wherein the modified third set of feature vectors are configured for use in ASR of the third unit of input speech.