1) American invention 
instrument for measuring sound levels
• (n.) An instrument for measuring sounds, as to their intensity, or the frequency of the vibrations.
<apparatus> An instrument for measuring sounds, as to their intensity, or the frequency of the vibrations. ... Origin: Phono-. ... (24 Mar 1998) ... 
Pho·nom'e·ter noun [ Phono- + -meter .] (Physics) An instrument for measuring sounds, as to their intensity, or the frequency of the vibrations. 
Type: Term Pronunciation: fō-nom′ĕ-tĕr Definitions: 1. An instrument for measuring the frequency and intensity of sounds.
phonometer 1. An instrument for measuring the pitch and intensity of sounds. 2. An instrument for measuring or automatically recording the number or force of sound-waves; phonometrics. Related 'measure' and 'metric' words and charts: mens-; Metric Chart of Units; Metric-Length Converter; ...