monaural
/mɑːˈɜːrəl/Definitions
1. adjective
relating to or involving sound in only one ear or channel, or in a single channel of a stereophonic system
“The new audio equipment features high-quality monaural sound reproduction.”
2. noun
a sound or audio signal that is received by only one ear or channel
“The monaural signal was difficult to distinguish from background noise.”