[f. sono- as combining form of L. sonus sound + -METER. In sense 1 perh. after F. sonomètre.]
1. An instrument for determining the number of vibrations made by a sonorous cord.
1808. Edinburgh Encycl. (1830), I. 128/1. Sonometers are instruments intended for determining the relation between the number of undulations which constitute the several notes of music.
1829. Chapters Phys. Sci., 273. In the experiments relative to this object, an instrument called a sonometer is made use of.
1873. W. Lees, Acoustics, I. iii. 23.
1889. Brinsmead, Hist. Pianoforte, 40. An extremely useful instrument called the monochord or sonometer.
2. An instrument for testing the sense of hearing, or the efficacy of treatment for deafness; an audiometer.
1849. Pract. Mech. Jrnl., Sept., 131. A most important instrument for the use of parties under treatment for deafness,… aptly named the sonometer.
1879. [see AUDIOMETER].
1894. Daily News, 14 June, 6/4. Amongst the illustrations of applied science were an ingenious sonometer…. It measures and tests the relative and comparative perception of hearing.
3. Electr. A telephone attached to an apparatus for testing metals by means of an induction-coil.
1879. Daily News, 31 Dec., 5/4. A difference which is at once indicated by a sound in a telephone attached, which is called the sonometer.
1881. Nature, XXIII. 520. The sonometer … is brought into the circuit.
