these bulging areas comprise opening 40 for housing light emitting diodes which continues from the front cover through the rear cover of the holder and which has a shape corresponding to but somewhat larger than the shape of the light emitting diodes as shown in fig4 and fig6 said small strip 34 is fitted into a line formed channel 42 formed between the front cover side of translucent window member 22b and body 22a accordingly a small strip 34 comprising a pair of light emitting diodes 36 is supported between speaker holder 22 and front cover 16 while storing the light emitting diodes 36 in the opening into translucent window member for the light emitting diodes as shown in fig5 and 6 and also in fig4 screw holes 44a 44b and 44c through which screws are to be bored are formed on speaker holder 22 namely two in the lengthwise direction in the upper part thereof and one in the lower part thereof the pair of screw holes 44a and 44b in the upper part are mounted above opening 24 which supports the speaker and screw hole 44c in the lower part is provided in a portion of translucent window member 22b on the one hand as shown in fig4 bosses 46a 46b and 46c with screw channels formed thereon protrude from the rear face of the front cover at positions corresponding to these three screw holes.