By the time most people could afford any of this equipment their hearing has probably degraded to such a point that they can only hear 12kHz to 14kHz anyway. A

By the time most people could afford any of this equipment their hearing has probably degraded to such a point that they can only hear 12kHz to 14kHz anyway. Although unscientific, I played some tones on youtube in the office and the twenty somethings could hear almost 20kHz and the forty somethings couldn't hear anything by the time the frequency sweep was just below 15kHz.