The harmonic-to-noise ratio applied to dog barks.

Dog barks are typically a mixture of regular components and irregular (noisy) components. The regular part of the signal is given by a series of harmonics and is most probably due to regular vibrations of the vocal folds, whereas noise refers to any nonharmonic (irregular) energy in the spectrum of the bark signal. The noise components might be due to chaotic vibrations of the vocal-fold tissue or due to turbulence of the air. The ratio of harmonic to nonharmonic energy in dog barks is quantified by applying the harmonics-to-noise ratio (HNR). Barks of a single dog breed were recorded in the same behavioral context. Two groups of dogs were considered: a group of ten healthy dogs (the normal sample), and a group of ten unhealthy dogs, i.e., dogs treated in a veterinary clinic (the clinic sample). Although the unhealthy dogs had no voice disease, differences in emotion or pain or impacts of surgery might have influenced their barks. The barks of the dogs were recorded for a period of 6 months. The HNR computation is based on the Fourier spectrum of a 50-ms section from the middle of the bark. A 10-point moving average curve of the spectrum on a logarithmic scale is considered as estimator of the noise level in the bark, and the maximum difference of the original spectrum and the moving average is defined as the HNR measure. It is shown that a reasonable ranking of the voices is achievable based on the measurement of the HNR. The HNR-based classification is found to be consistent with perceptual evaluation of the barks. In addition, a multiparametric approach confirms the classification based on the HNR. Hence, it may be concluded that the HNR might be useful as a novel parameter in bioacoustics for quantifying the noise within a signal.

Nasopharyngeal diseases in cats: a retrospective study of 53 cases (1991-1998).

The records of 53 cats with nasopharyngeal disease were examined. Of the cats with nasopharyngeal disease, 49% had lymphosarcoma and 28% had polyps. Clinical signs in these cats were compared to 24 cats with nasal disease alone. Cats with only nasal disease more commonly had historical nasal discharge and sneeze, whereas cats with nasopharyngeal disease more often had stertorous respiration, phonation change, and typically reported less nasal discharge or sneeze. It is important to include nasopharyngeal disease in the differential diagnosis for cats with nasal discharge, sneeze, stertor, or phonation change.

Bradycardia, altered thermographic patterns, and dysphonia associated with cervical laxity in an Ankole-Watusi bull.

A native African bull was examined for ataxia of 10 days' duration. Clinical signs included bradycardia, ataxia, hypermetria, and dysphonia. Cerebrospinal creatine kinase activity was high. Thermographic evidence of bilateral accessory nerve dysfunction was observed. This finding was supported by electromyographic studies. Survey and positive contrast radiographs were nondiagnostic. Clinical signs exacerbated after radiographic examination. Treatment included dexamethasone and flunixin meglumine administered IV.