Explanation of two units have been frequently used to measure the magnitude of loudness, phon and sone

Read the following essay questions carefully below and write your essay. 1. Two units have been frequently used to measure the magnitude of loudness, phon and sone. Please explain their meanings and the detailed procedure to how to measure them. 2. Hearing-impaired listeners generally have difficulty in perceiving sounds in noise. Please explain at least two major reasons for their difficulty. Guideline for the essay: Please read the guideline carefully and follow them. 1. The essay should be typed on a computer using a 12 font size and double space. 2. The length of the essay should be within 3-4 pages. 3. Use APA writing style. 4. Work independently (copying texts and/or materials from other fellow students, textbooks, journal articles or other online publications with no reference and citation is considered as cheating or plagiarism and may cause serious disciplinary actions).