Timely addition of human-perceptible audio to mask an audio watermark

A computing system comprising:

• at least one processor;
• non-transitory data storage;
• and
• program instructions stored in the non-transitory data storage and executable by the at least one processor to carry out operations including:
• receiving a media stream that defines a sequence of audio content, and
• modifying the media stream to produce a modified media stream that defines the sequence of audio content, and outputting the modified media stream,
• wherein the modified media stream includes an audio watermark that is machine-detectable to trigger an interactive event,
• wherein modifying the media stream comprises adding into the media stream a combination of (i) the audio watermark and (ii) supplemental audio content coincident with the audio watermark, wherein the supplemental audio content being coincident with the audio watermark is to help mask the audio watermark when the modified media stream is presented by a content presentation device.

A non-transitory computer-readable medium having stored thereon program instructions executable by at least one processor to carry out operations comprising:

• receiving a media stream that defines a sequence of audio content;
• and
• modifying the media stream to produce a modified media stream that defines the sequence of audio content, and outputting the modified media stream,
• wherein the modified media stream includes an audio watermark that is machine-detectable to trigger an interactive event,
• wherein modifying the media stream comprises adding into the media stream a combination of (i) the audio watermark and (ii) supplemental audio content coincident with the audio watermark, wherein the supplemental audio content being coincident with the audio watermark is to help mask the audio watermark when the modified media stream is presented by a content presentation device.