HEADPHONES: Factors that Influence Listeners’ Preferred Bass and Treble Levels in Headphones?

Sean Olive writes:

Most people would agree that headphone purchase decisions are heavily influenced by the brand and styling (size,  weight, color, quality of  materials).   But what is considered stylish and fashionable  by me is not shared by my 15-year old daughter (this week donning purple hair), and vice versa. In other words, the visual aesthetic  of the headphone  is really in the the eye and mind of the beholder, and can vary with age, gender, culture, and other demographic category.

But what about sound quality?  To what extent does the consumer's  age, gender, culture and prior listening experience influence their taste in headphone sound quality?  Is there a scientific basis for headphone manufacturers to design headphones that have different amounts of bass and treble aimed to satisfy the tastes of a targeted demographic group?

To answer this question, we recently .........