Fredrik Lindgren

Hearing in Classical Musicians

(1981). Hearing in Classical Musicians. Acta Oto-Laryngologica: Vol. 91, No. sup377, pp. 1-100.

Is There a Relationship Between Hypercholesterolaemia and Noise-induced Hearing Loss?

Many investigators who have analysed the possible correlation between hearing loss and high serum cholesterol levels have found that hearing appears to be influenced by high blood lipids. Noise, as is well known, also influences hearing, particularly at high frequencies. It increases serum cholesterol levels during short-term experiments. The present investigation addresses the question of a possibly increased ototraumatic influence by the combination of high serum cholesterol levels and occupational noise exposure. Seventy-eight 50-year-old men with high serum cholesterol levels from a WHO study were compared with 75 50-year-old men who were randomly selected from the same WHO material. Group mean audiograms showed that hearing was similar in both groups, with a moderate high frequency hearing loss having a configuration suggestive of a noise-induced hearing loss. Analysis of the individual histories and the pure-tone audiograms showed that noise was the most predominant factor influencing hearing at any specific frequency or combination of frequencies. There was a statistically significant tendency for the high-cholesterol group that had suffered the most noise exposure, to have a high-frequency hearing loss. There was also a tendency for the low-cholesterol group to have a high-frequency loss if they had been excessively exposed to occupational noise. No further correlations were found. The present results indicate a slightly increased risk of acquiring a high-frequency sensorineural hearing loss for people who work in noisy environments and have high serum cholesterol levels.

The Influence of Inner Ear Melanin on Susceptibility to TTS in Humans

In order to investigate the function of the inner ear melanin, the relationship between skin pigmentation and noise-induced temporary hearing loss (TTS) was studied. Forty-four normal-hearing Caucasian subjects were divided into three groups according to their sun sensitivity. Hearing thresholds before and after exposure were ascertained with a computerized sweep frequency audiometer in the frequency range 2-8 kHz. The noise exposure consisted of a 1/3-octave band-filtered noise with a centre frequency of 2 kHz at 105 dB SPL for 10 min. The mean TTS in the frequency range 2-8 kHz showed statistically significant differences between the three groups, i.e. the most pigmented subjects developed least TTS, and the least pigmented subjects most TTS.

Hearing In Pop Musicians

Comparatively few previous studies have investigated the hearing of pop musicians. On the average, a surprisingly low percentage (5%) of hearing loss was demonstrated in 160 pop musicians. The pres...

Pop music and hearing.

Several factors indicate the possibility of sensorineural hearing loss in connection with pop music. However, very few investigations have examined the hearing in pop musicians and their audience. Sensorineural hearing loss was only demonstrated in 5% of musicians. In our own material, we found a sensorineural hearing loss in 13% defined as a mean pure-tone threshold at 3, 4, 6. and 8 kHz of more than 20 dB HL. The hearing loss was, as expected, correlated with age, duration of exposure, military service. etc. Temporary threshold shift measurements showed that musicians were more resistant to pop music noise than the audience and that female listeners were more resistant than male listeners. The findings leave many interesting questions concerning the relationship between noise and hearing loss.

The Interaction of Smoking and Noise on Temporary Threshold Shifts

Four separate experiments examined the effects of cigarette smoking on temporary threshold shifts (TTS) following noise exposure. One experiment compared smokers and non-smokers after the subjects had abstained from smoking for at least 6 h. A second experiment tested only smokers who smoked a cigarette just before noise exposure, during the noise exposure and in a control condition during which they did not smoke. A third experiment tested only non-smokers who were exposed to noise after chewing nicotine gum or after a control condition in which they rested without chewing the gum. A fourth experiment tested smokers and non-smokers in one condition which required them to smoke a cigarette just prior to noise exposure and in another condition which prevented them from smoking. The results indicate that smokers consistently evidence slightly smaller TTS than do non-smokers. Non-smokers evidenced significantly greater TTS at one frequency after they had chewed nicotine gum than when they had not. These results suggest that the smaller TTS associated with cigarette smoking is related to both the chronic and the acute effects of smoking and that these effects may be more attributable to carbon monoxide than to nicotine.

Temporary Threshold Shift after Exposure to Pop Music

Temporary threshold shift (TTS) was studied in pop musicians as well as in listeners. It appears that TTS is less pronounced in pop musicians than in listeners. This can only in part be explained by slightly inferior hearing threshold levels than in the audience before exposure. Further, male listeners showed more TTS than female listeners. After 2 hours of exposure to live pop music a TTS2 appears in pop musicians after an exposure to 98 dB(A) as opposed to listeners where TTS2 appears at 92 dB(A). When the present results are related to the CHABA risk criteria it seems that exposure to live pop music at 100 dB(A) for 2 hours is a limit which should not be exceeded if the risk of permanent hearing loss is to be avoided.

The Effects of Smoking and Physical Exercise on Temporary Threshold Shifts

The Temporary Threshold Shifts (TTS) of 9 habitual smokers and 9 non-smokers were determined twice (via Békésy sweep procedures) after each of three conditions: 10 min of physical exercise, 10 min of 105 dB SPL exposure to a third octave band noise centered around 2 kHz, and 10 min of both exercise and noise. Smokers evidenced less TTS than did non-smokers, particularly when exposed to both noise and exercise and especially in the range of 2.5 to 5 kHz. Heart rate and systolic blood pressure increased more for smokers than for non-smokers, particularly when they were required to exercise. Oral temperature was positively correlated with the magnitude of TTS.

Temporary threshold shift after exposure to noise and music of equal energy.

Ten voluntary subjects were exposed to 10 min of recorded pop music on five occasions. On five other occasions these subjects were exposed to a noise with level-, frequency-, and time-distribution characteristics, measured in octave-band steps, equal to those of the music. Measurements of temporary threshold shift showed almost equal sensitivity to the two stimuli in four subjects, whereas six others demonstrated marked differences in sensitivity. Differences were always due to more temporary threshold shift after exposure to the nonmusical noise stimulus. These findings imply that factors other than physical properties of the fatiguing sound contribute to the degree of temporary threshold shift.

Does Pop Music Cause Hearing Damage

Relatively few investigations have so far reported on the hearing in pop musicians. In summary, these have shown a sensorineural hearing loss in 5%. This study was carried out on 83 professionals working with pop music. Depending upon how hearing loss is defined, we found a sensorineural loss in 13-30% of the pop musicians. Hearing losses were slight. It appears that the risk for hearing damage for the audience is small. A limit for presentation of the music at 95 dB (A) is suggested as a compromise satisfying both audiologists and audience.