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Following an information campaign through the media on the subject of 'andropause', 81 consecutive self-referred patients were evaluated. At presentation these patients had complaints possibly related to partial androgen deficiency in the aging male. Hormonal parameters were measured and specific aging male questionnaires, such as Androgen Deficiency in Aging Male (ADAM) and Aging Males' Symptoms (AMS) scale questionnaires were completed. The median age was 59 (range 53-66) and mean body mass index (BMI) was 26.4 +/- 3.3 kg/m2. Mean testosterone was 479.8 +/- 149.0 ng/dl and mean free testosterone was 10.0 +/- 3.0 ng/dl. Only 7.1% of all patients were diagnosed with 'idiopathic' ADAM. The majority of patients presented with erectile dysfunction. A wide variety of conditions were diagnosed, including hemochromatosis, micro- and macroprolactinoma, hypothyroidism, benign prostate hypertrophism and prostate carcinoma. The scores of AMS psychological, somatovegetative and sexual subscales were 12, 16 and 13, according to AMS classification corresponding to severe, moderate and severe complaints, respectively. There was no correlation between AMS (total and subscales) and testosterone levels. A positive correlation between the somatovegetative subscale of the AMS and both BMI and insulin was found. In conclusion, we observed that in a group of self-referred men andropause is not a frequent diagnosis, and other pathology needs to be addressed requiring a multi-disciplinary approach.

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When the acoustic stimulus consists of two sinusoidal components (frequencies f• and fa), the impulses of a single auditory-nerve fiber can show partial synchrony with either of these components (provided the frequencies stay below approx 5 kHz). Often a synchrony with an externally generated combination tone of frequency 2ft --f• can be detected as well. It is shown in this letter that such a behavior is a logical consequence of the assumption that nerve impulses are elicited at the peaks of the stimulus waveform. In addition, it is demonstrated that only special combination tones will show this phenomenon. Many of the experimental results on this type of synchrony can be explained in this way. It is thus not necessary to assume that a special physiological mechanism is responsible for the observed synchrony per se. But deviations from the basic properties derived here should be observed closely, because these do give useful indications about cochlear physiology. FoR A SINUSOIDAL STIMULUS TONE, TIlE FIRINGS OF AN AUDITORY-nerve fiber often show some degree of synchrony with the period of the stimulus. When the stimulus consists of two tones, with frequencies f• and/•., synchrony can often be detected with either of the constituent tones (Hind ½t •l., 1967). In their recent paper, Goldstein and Kiang (1968) present evidence that in this case the firings are also synchronous to the combination tone with frequency 2f•-/•., although the latter tone does not belong to the stimulus. These experimental data suggest that a nonlinear mechanism producing combination tones is responsible for such a firing pattern.The purpose ooe this Letter is to show that this conclusion is not necessarily true. It cannot be denied that certain nonlinear mechanisms are at work in the cochlea that tend to add combination tones to the effective stimulus. Yet, it is shown that, without such a mechanism, synchrony with certain combination tones that are not contained in the stimulus should be observable. The only prerequisites are that a nerve impulse be elicited whenever some effective excitation signal passes a certain preset threshold and that the effective excitation signal does not contain other components than the stimulus. The proof proceeds in three steps. First, it is assumed that the two stimulating tones are harmonically related; second, this restriction is removed by a method that is similar to the one used in studying the sensitivity of the ear to phase relations between signal components (de Boer, 1961); and third, the result of the discussion is compared with deductions from the theory of cross-correlation functions.Let us first assume that the two stimulating tones are harmonically related, i.e., that their frequencies fl and f2 are adjacent harmonics of a common fundamental frequency f0: fl=nfo, f2= (n-kl)fo. The relation y (t) = coso•lt-kcoso•st = 2 cos« (oa-ko•2)t cos«reduces to y (t) = 2 cos2,r[ (2n+ 1)/2Jfot cos2,r(fo/2)t.In Fig. l(a), the stimulus signal y(t) is shown; the dashed line indicates the "envelope-generating s...