Sound Instruments

The Sages forbade playing musical instruments on the Sabbath because a musician may become so absorbed in his music that if a string snaps he will forget it is the Sabbath and repair it. This is a general prohibition for any instrument that is designated to produce sound even if the instrument is not repairable after it breaks. Therefore, it is forbidden to use a door knocker that is encased in a steel box because the person is producing sound with an implement designated to produce sound even though it is not repairable due to the steel encasing.

This prohibition extends to electric sound- producing instrument such as radio, telephone, microphone, loudspeaker, intercom, earphone and hearing aids that produce sounds intelligible to the ear. This prohibition does not apply to a hearing aid that works on the bone induction method where the sound itself is heard only as unwanted noise but when these vibrations are applied to a specific bone in the ear they are then understood as speech. This type of sound was never forbidden. Furthermore, we have no grounds to forbid it on the basis that we suspect that perhaps he may fix it if it breaks. The reason is that there is a only a remote probability that it will break specifically on the Sabbath and even if it does happen, it can only be repaired at the factory.

The original electric-sound producing instruments were built with vacuum tubes that worked with red hot thin metal wires or plates set within these tubes. They were similar to the light bulb. When the device was turned on these metal wires or plates became red hot. When the sound was increased, in some of the vacuum tubes the electrical power increased the heat of the metal in the tubes. When the sound was turned down the reverse happened and the heat was decreased. The same effect was true with a microphone when the speaker raised or lowered his voice. This heating of the metal wires or plates was necessary for the device to function and when operating such devices on the Sabbath he violated the Biblical work of kindling a fire and the Rabbinical work of quenching a glowing hot metal fire.

Modern military tanks are equipped with liquid microphones. Speech creates vibrations within the liquid that travels through it reproducing his voice by vibrations at the other end. This works on the same principle as musical instruments where the sound is being produced by an instrument through vibrations. The human voice itself is not heard. It is therefore forbidden.

The "Laminar Proportional Amplifier" (LPA), is a mechanical loudspeaker device that works without electricity. It was designed for use in high combustion areas, and for military ships that need to preserve communications in combat situations. The system operates through an air tank or an air compressor. The air flow pressure is set beforehand, and speech does not have any effect on the operation of the compressor. The manufacturer, DRT Mfg. Co. Inc. of Rockville, Maryland, claim that their LPA system works without a diaphragm and that such models have been demonstrated in synagogues.

The system amplifies speech, being defined as an acoustic pressure wave. This wave is forced by the airflow into square laminates with acoustically designed cutouts. The sound wave in the control channel is moved by the jet laterally at the sound frequency, thus increasing the acoustic wave ten fold.

The LPA system does not produce new sound, it merely amplifies a voice. This is comparable to an echo or speaking through a horn. It is therefore, not under the prohibition of producing sound. Nevertheless, to an outside viewer it appears very much like an electrical amplifier, thus giving the impression of a weekly mundane act (uvdah dchol). Furthermore, if the affluent synagogues will employ this system in their standard design then the members of the not so affluent synagogues would demand the same in an affordable electrical amplifier system.

The estimated cost of such a system for those large rooms needing voice amplification is between three to five units at ten thousand dollars per unit. In most problematic cases it would be much less costly to redo the interior acoustic design by using hard material that reflects sound, for the walls and ceiling, and acoustically designed sound reflectors. For the situation where for the High Holy Days they remove the movable walls surrounding the main sanctuary, thus greatly expanding the prayer area, redoing the acoustics may not work. In such a situation, where the choice is either using the LPA system or using an electrical amplifier system it would be permitted to use the LPA system. To defer costs it may be possible to rent the system.

Most electric sound machines are turned on for short periods and not for many days. Therefore, if he turns them on he does not violate the Biblical prohibition of making an implement. If, when turned on they may be turned off immediately thereafter and there is no fixed time for them to remain on then there is no Rabbinical prohibition of making an implement by turning them on. This law includes using telephones, microphones, loudspeakers, radios, electrical music instruments, cassettes players and the like. These instruments may be turned on or off immediately thereafter. An intercom however, is made to be turned on and left on for more than six months. Some places of business shut off the electrical power at the end of the day and operate the alarm system through backup batteries. This however, is not the general rule and the intercom is not closed at the end of the day in the vast majority of places. Therefore, turning on an intercom is comparable to turning on an electric watch, (see chapter one). Since these implements are set in motion for a long period of time, the act of setting them in motion is itself an integral part of completing the implement and not just using it. Consequently, turning on the intercom to remain on for more than six months is a violation of the Biblical work of making an implement and also a violation of the Rabbinical work of kindling a fire because of the sparks created when turning on the switch. Talking into the intercom is a violation of the Rabbinical work of producing sound through an on the Sabbath. Battery-operated intercoms are turned on to stay on for the length of the batteries which is generally less then six months. If however, it will last more than six months he violates a Biblical work of making an implement when he turns it on. If it will not last six months he violates a Rabbinical prohibition of making an implement. If the sparks created by turning it on are cold sparks that cannot ignite even highly combustible fuel then he does not violate the work of kindling a fire. If he only turns down the voice of the intercom to preserve the machines but leaves the power on in order to hear the beep he violates the work of dismantling. This is because the vast majority of the time the intercom is turned on to talk. Therefore, turning on the voice is part of completing the implement and turning it off is dismantling the implement.

If the talk button of the intercom was left on for the Sabbath unintentionally, he may converse if needed in the vicinity of the intercom although his voice is being amplified by the second intercom. The reason is the same as discussed before with making an implement: since he has no intention to create the sounds or to create an implement, it is not forbidden. The same is true with talking to a person who uses a hearing aid on Sabbath. If the speaker speaks loudly and slowly so that the listener can hear him without the hearing aid or he can understand him by reading his lips and he does not intend to speak into the hearing aid, then he may speak to him. This rule is limited to cases where it is not apparent that he is using the instrument. If, however, he talks into a loudspeaker even though his lips are not directly facing it but it is apparent that he intends to use it, he is guilty of using a sound producing instrument on the Sabbath.

Old telephone switchboard systems have incandescent bulbs that light up when a telephone connection is made. If these bulbs are not needed for the connection itself then as far as the user is concerned he does not intend to turn them on but only to make the connection, and it is Rabbinically forbidden. If these bulbs are needed to make the connection then he violates the Biblical work of kindling a fire. Today's modern switching system works by computers. Some systems still have LED lights that go on when a connection is made. These LED lights are cold lights and are not a violation of kindling a fire. They are also not forbidden as an information system (implement) because he does not see it from his home nor does it interest him in this capacity. Therefore, if he does not intend to make an implement it is not considered an implement. Furthermore, since there is no minimum time he must talk on the telephone, there is no minimum time the LED light must remain on and it is not in the category of making an implement. The same is true for the LED lights on a modern telephone that light when the telephone is in the speaker mode and go off when the telephone is turned off. However, the tone mode of the telephone produces sounds to inform the user that the number was entered properly. This tone is desired and is a violation of the Rabbinical prohibition of producing sound on the Sabbath. It is, therefore, advisable that a doctor use a simple rotary phone unless he needs the tone to connect faster or automatically to the hospital or emergency services. Wherever possible, a doctor should screen his calls on Sabbath by using an answering machine telling the caller that if this is an emergency that cannot wait until after Saturday to describe his symptoms and leave his telephone number. If the doctor feels this method will not work because the patient may judge incorrectly that he could wait, then perhaps he will find another way to do it.

As long as he talks without interruption over the telephone, he violates only one prohibition of producing sound on the Sabbath. If he stops to listen to the other party and then answers him, each time he stops to listen and starts talking again he violates this prohibition.

The prohibition of creating sounds on the Sabbath is not a prohibition on each and every different noise or on each word that he speaks over the telephone line. As long as he is talking or playing an instrument uninterruptedly he violates one prohibition. If he pauses to listen to someone else or to rest, when he resumes he violates this prohibition again. When adjusting a radio he turns it higher and lower and changes channels. This is comparable to a musician playing on one string and then moving to another to change the sound and pitch. If after adjusting the radio he returns to change the sound by changing the station and this way he causes new sounds to be heard, or he increases or decreases the amplification, he again violates this prohibition. When talking into a microphone the amplifier increases and decreases the amplification as the speaker raises and lowers his voice. Therefore, if the speaker during his talk turns the amplifier knob to increase or decrease his voice, it is part of the talk and considered one violation.

Hearing aids that work on the same principle as a telephone, where a transmitted voice is heard when placed near the ear, are forbidden to be worn on the Sabbath. The reason is that he causes people to violate the prohibition of creating sound on Sabbath when they speak into the device and the wearer also violates this prohibition when he speaks because he desires to know if he spoke correctly.

A hearing aid that works on the bone induction principle as explained before may be used on the Sabbath since the sounds are unintelligible when placed near the ear. However, it must be turned on before Sabbath. If it was not turned on before the Sabbath due to negligence or it was accidentally turned off, it should be turned on in an unusual manner such as by using the back end of a spoon or knife to push the button.

There are varying opinions on whether one is allowed to wear a hearing aid when entering into a public domain. The question is since it is not an implant and is constantly inserted and removed is it considered carrying on Sabbath? Or since he needs it, is it considered wearing an object such as wearing eyeglasses? It is my opinion that the bone induction hearing aid may be worn on the Sabbath.

If a radio was opened on the Sabbath by a timer or by a non-Jew he should leave the room so as not to cast suspicion on himself that he turned it on. If he must remain in the room he should ignore the radio for the same reason. If it is on at a very low volume and no one else will know about it, he is still not permitted to set the timer before Sabbath because playing the radio on the Sabbath is disrespectful. If it is necessary to hear broadcasts about a dangerous weather situation or the like, he should put it on a very low volume and cover it so that he does not forget that it is Sabbath and amplify the sound or change the station unnecessarily. A broadcast coming from a foreign country that Jews are producing on Sabbath is forbidden to be heard even if it is not yet Sabbath for the listener, because he is benefiting from the desecration of the Sabbath.

It is prohibited to leave on the fax machine or answering machine for Sabbath because when he turns it on his intention was that it remain on for the Sabbath and his intention was for business purposes. This therefore, will cause a desecration of the Torah when a Jew will place an order because he will say, if an Orthodox Jew leaves it on then it must be permitted. Faxing on the Sabbath is a violation of the work of writing.

Eyeglass lenses that automatically change colors when in sunlight to function like sunglasses or lenses that automatically adjust to near and far distances are permitted to be used on the Sabbath. The reason is that they were constructed and are used to constantly change back and forth and do not have to remain in any one state for any feasible length of time.

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