494 



GuYE*s hearing-apparatus. New model of large size (receiving funnel 191 cm2). 

 Table showing how many times the sound is reinforced r>s compared with a 

 receiving funnel of about the width of the auricle (21 cm^). 



In theory it is especially the avemge that exceeds considerably 

 the amount of reinforcement generated by enlargement of tlie receiver. 

 To all appearance this is due to the distribntion of the energy and 

 to the peculiar faculty of the resonator to attract sonnd. This phe- 

 nomenon is most distinct when we choose hearing-apparatus whose 

 receiver has the width of the comparison-funnel i.e. the width of 

 the auricle. 



