**Author details**

**Closed headphones** are the headphones which have the back of the earcups closed. Closed headphones isolate the ear from external ambient noise and minimize the music leakage out

**Dynamic compression** is a signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds by narrowing an audio signal's dynamic range. The device

**Earphones** are electroacoustic transducers which converts an electrical signal into acoustical

**Energy dose** is the integral of the square of acoustic pressure over time. The units of energy

**Front of House (FOH)** is the part of a performance venue which is open to the public, for example, an auditorium and foyer. Front of house sound engineer is normally positioned in a small sectioned‐off area front of house, surrounded by the audience or at the edge of the audience area. From this position, he has unobstructed hearing and a clear view of the performance, enabling the operation of the speaker system, show control consoles and other equipment. In this case, Front of House can refer to both the general audience/public area or

**Headphones** are a pair of earphones connected with a bail which is put on the head. The bail

**Hearing level (HL)** is defined in a similar way as the SPL (see below), except the reference level which is equal to normal threshold of hearing for a given frequency. Hearing level is

**Inside or inner earphones** are very small earphones which are inserted directly into ear canal. **Loudspeakers** are electroacoustic transducers, which convert an electrical signal into acoustical one and radiate it into space. The loudspeakers occur most often as loudspeaker sets,

**Open headphones** have the back of the earcups open. The sound in the ear canal does not depend on the downforce of the earphones to the ears. Open headphones do not block out

**Permanent threshold shift (PTS)**is a permanent shift in the auditory threshold. It may occur suddenly or develop gradually over time. A permanent threshold shift results in permanent hearing

**Public address (PA)** is an electronic sound amplification and distribution system, used to delivery sound with sufficiently high SPL to the public in large spaces: railway stations, air-

**Semi‐open headphones** are a compromise between open and closed headphones. They com-

which consist of a few single loudspeakers, enclosure, filters, amplifiers etc.

h. It is also known as sound exposure.

which realizes dynamic compression is called a compressor.

to the specific small section from where the show is operated.

provides the necessary downforce of earpieces to the ears.

applied in audiometry for determination of hearing loss.

ambient noise and allow audio leakage out of the earpieces.

ports, stadiums, department stores etc.

bine all the positive properties of both designs.

one and deliver it directly to the ear.

s and Pa2

of the earpieces.

182 Advances in Clinical Audiology

dose are Pa2

loss.

Andrzej Dobrucki\*, Maurycy J. Kin and Bartłomiej Kruk

\*Address all correspondence to: andrzej.dobrucki@pwr.edu.pl

Department of Acoustics and Multimedia, Faculty of Electronics, Wroclaw University of Science and Technology, Wrocław, Poland
