TTS2 after Exposure to Music by Open Typed Headphone

• Published in: AUDIOLOGY JAPAN Vol. 29; no. 3; pp. 164 - 170
• Main Authors: Oishi, Yuichiro, Ino, Tadahiko, Koga, Keijiro, Hanamoto, Masahiro
• Format: Journal Article
• Language: English
• Published: Japan Audiological Society 1986
• ISSN: 0303-8106; 1883-7301
• DOI: 10.4295/audiology.29.164

The TTS2 hypothesis states that a temporary threshold shift measured at 2 minutes after cessation of an 8 hours noise exposure closely approximates the permanent threshold shift (PTS) incurred after a 10-20 years exposure to that same level. 1) TTS2 in young subjects aged from 19 to 23 years were measured by intensive music sound generated from an open typed headphone at 108dB (SPL) for 4 hours. The values of TTS2 at 2000-8000Hz were 10-17dB. 2) TTS2 in 3 subjects aged about 30 years, 40 years and 50 years old were measured by 117dB (SPL) sound for 1 hour. TTS2 values in the former 2 subjects were 8-10dB at 2000-8000Hz, in the other subject PTS of 40dB at 8000Hz was revealed. 3) The intensity of sound at 30cm distance from a headphone generating tone of 108dB (SPL) at ears were 55dB (A). In this condition those ears could not hear the voice of 90dB (A) at 1 meter distance from the headphone.