An acoustic horn is accessed. The acoustic horn is coupled to a head of a user. Audio from a whispered voice of the user is obtained. The whispered voice includes one or more words. The words can comprise a full natural language input. A signal processing module generates audio data. The audio data is based on the whispered voice that was obtained. The audio data is translated, by an automatic speech recognition (ASR) model, into text. The text corresponds to the one or more words. The ASR model can send the text to a large language model (LLM). The acoustic horn transmits sound energy from the user to the signal processing module. The acoustic horn includes one or more impedance matching layers.